$FSLY
Fastly, Inc. Stock $fsly

$fsly Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000151741324000048 Filed on February 22, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$133.5M	$137.8M	$506.0M
YoY Change	13.57%	15.47%	16.93%
Cost Of Revenue	$60.29M	$62.00M	$239.7M
YoY Change	5.19%	9.28%	7.5%
Gross Profit	$73.23M	$75.77M	$266.3M
YoY Change	21.54%	21.08%	26.96%
Gross Profit Margin	54.85%	55.0%	52.64%
Selling, General & Admin	$76.65M	$80.09M	$307.9M
YoY Change	9.34%	8.45%	2.39%
% of Gross Profit	104.66%	105.69%	115.59%
Research & Development	$38.25M	$38.27M	$152.2M
YoY Change	2.18%	2.88%	-2.01%
% of Gross Profit	52.23%	50.51%	57.14%
Depreciation & Amortization	$18.18M	$18.48M	$72.03M
YoY Change	51.47%	8.98%	69.08%
% of Gross Profit	24.82%	24.38%	27.04%
Operating Expenses	$119.5M	$118.4M	$460.0M
YoY Change	11.13%	6.59%	0.89%
Operating Profit	-$46.26M	-$42.58M	-$193.7M
YoY Change	-2.15%	-12.13%	-21.32%
Interest Expense	$3.269M	$3.840M	$14.14M
YoY Change	169.5%	149.35%	140.11%
% of Operating Profit
Other Income/Expense, Net	-$89.00K	-$763.0K	-$1.832M
YoY Change	-64.4%	-1758.7%	6217.24%
Pretax Income	-$43.08M	-$23.85M	-$133.3M
YoY Change	-3.3%	-49.12%	-30.09%
Income Tax	$347.0K	-$465.0K	-$221.0K
% Of Pretax Income
Net Earnings	-$43.43M	-$23.39M	-$133.1M
YoY Change	-2.82%	-49.87%	-30.24%
Net Earnings / Revenue	-32.52%	-16.97%	-26.3%
Basic Earnings Per Share	-$0.32		-$1.03
Diluted Earnings Per Share	-$0.32	-$0.18	-$1.03
COMMON SHARES
Basic Shares Outstanding	134.2M shares	130.8M shares	128.8M shares
Diluted Shares Outstanding	134.6M shares		128.8M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments	$329.5M	$328.8M	$322.7M
YoY Change	-39.72%	-36.52%	-37.7%
Cash & Equivalents	$124.4M	$107.9M	$21.17M
Short-Term Investments	$185.4M	$220.9M	$280.3M
Other Short-Term Assets	$23.21M	$20.46M	$20.46M
YoY Change	-21.91%	-29.3%	-29.3%
Inventory
Prepaid Expenses
Receivables	$107.5M	$120.5M	$120.5M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$460.2M	$463.7M	$463.7M
YoY Change	-30.44%	-27.15%	-27.15%
LONG-TERM ASSETS
Property, Plant & Equipment	$252.5M	$231.8M	$231.8M
YoY Change	40.33%	-6.83%	-6.83%
Goodwill	$670.4M	$670.4M
YoY Change	0.03%	0.03%
Intangibles	$57.58M	$62.48M
YoY Change	-25.92%	-24.64%
Long-Term Investments	$1.743M	$6.088M	$6.088M
YoY Change	-98.52%	-96.31%	-96.31%
Other Assets	$63.56M	$90.78M	$90.16M
YoY Change	-32.95%	-1.99%	-2.66%
Total Long-Term Assets	$1.046B	$1.062B	$1.062B
YoY Change	-12.91%	-15.73%	-15.73%
TOTAL ASSETS
Total Short-Term Assets	$460.2M	$463.7M	$463.7M
Total Long-Term Assets	$1.046B	$1.062B	$1.062B
Total Assets	$1.506B	$1.525B	$1.525B
YoY Change	-19.14%	-19.56%	-19.56%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$5.485M	$5.611M	$5.611M
YoY Change	17.5%	17.24%	17.24%
Accrued Expenses	$55.52M	$61.82M	$83.19M
YoY Change	31.23%	1.07%	-1.19%
Deferred Revenue	$38.24M	$33.82M
YoY Change	55.45%	20.6%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$11.97M	$15.68M	$15.68M
YoY Change	-51.65%	-45.83%	-45.83%
Total Short-Term Liabilities	$120.2M	$147.7M	$147.7M
YoY Change	-3.97%	-3.04%	-3.04%
LONG-TERM LIABILITIES
Long-Term Debt	$344.3M	$343.5M	$345.1M
YoY Change	-51.19%	-51.26%	-52.08%
Other Long-Term Liabilities	$49.61M	$4.416M	$52.90M
YoY Change	707.5%	-37.59%	-22.68%
Total Long-Term Liabilities	$393.9M	$347.9M	$398.0M
YoY Change	-44.64%	-51.12%	-49.53%
TOTAL LIABILITIES
Total Short-Term Liabilities	$120.2M	$147.7M	$147.7M
Total Long-Term Liabilities	$393.9M	$347.9M	$398.0M
Total Liabilities	$514.1M	$545.7M	$545.7M
YoY Change	-43.12%	-42.01%	-42.01%
SHAREHOLDERS EQUITY
Retained Earnings	-$878.2M	-$834.8M
YoY Change	17.66%	18.97%
Common Stock	$3.000K	$3.000K
YoY Change	50.0%	50.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$991.8M	$979.5M	$979.5M
YoY Change
Total Liabilities & Shareholders Equity	$1.506B	$1.525B	$1.525B
YoY Change	-19.14%	-19.56%	-19.56%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	-$43.43M	-$23.39M	-$133.1M
YoY Change	-2.82%	-49.87%	-30.24%
Depreciation, Depletion And Amortization	$18.18M	$18.48M	$72.03M
YoY Change	51.47%	8.98%	69.08%
Cash From Operating Activities	$11.13M	-$7.378M	$362.0K
YoY Change	-225.63%	-39.17%	-100.52%
INVESTING ACTIVITIES
Capital Expenditures	$8.448M	$8.598M	$32.27M
YoY Change	141.79%	-63.79%	61.54%
Acquisitions			$0.00
YoY Change			-100.0%
Other Investing Activities	$42.13M	-$28.65M	$327.2M
YoY Change	-81.46%	-129.74%	3.52%
Cash From Investing Activities	$33.68M	-$37.25M	$294.9M
YoY Change	-84.66%	-151.31%	25.11%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$10.73M
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-1.880M	-117.8M	-331.4M
YoY Change	-67.09%	2250.96%	75.2%
NET CHANGE
Cash From Operating Activities	11.13M	-7.378M	362.0K
Cash From Investing Activities	33.68M	-37.25M	294.9M
Cash From Financing Activities	-1.880M	-117.8M	-331.4M
Net Change In Cash	42.94M	-162.5M	-36.08M
YoY Change	-79.06%	-392.95%	54.05%
FREE CASH FLOW
Cash From Operating Activities	$11.13M	-$7.378M	$362.0K
Capital Expenditures	$8.448M	$8.598M	$32.27M
Free Cash Flow	$2.684M	-$15.98M	-$31.91M
YoY Change	-121.72%	-55.46%	-64.39%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	128770000	shares
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	128770000	shares
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-190774000	usd
CY2023	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	565000	usd
CY2022	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-255000	usd
CY2021	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-286000	usd
CY2023	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	7713000	usd
CY2022	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-6404000	usd
CY2021	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-2347000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-6659000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-225330000	usd
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	usd
CY2023	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-648000	usd
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-3688000	usd
CY2023	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	32945000	usd
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0001517413
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2023	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1	segment
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-38897
CY2023	dei	Entity Registrant Name EntityRegistrantName	FASTLY, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	27-5411834
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	475 Brannan Street, Suite 300
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	San Francisco
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	CA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	94107
CY2023	dei	City Area Code CityAreaCode	844
CY2023	dei	Local Phone Number LocalPhoneNumber	432-7859
CY2023	dei	Security12b Title Security12bTitle	Class A Common Stock, $0.00002 par value
CY2023	dei	Trading Symbol TradingSymbol	FSLY
CY2023	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	2000000000	usd
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	134200000	shares
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	235700000	usd
CY2023	dei	Auditor Firm AuditorFirmId	34
CY2023	dei	Auditor Name AuditorName	Deloitte & Touche LLP
CY2023	dei	Auditor Location AuditorLocation	San Francisco, California
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	107921000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	143391000	usd
CY2023Q4	us-gaap	Marketable Securities Current MarketableSecuritiesCurrent	214799000	usd
CY2022Q4	us-gaap	Marketable Securities Current MarketableSecuritiesCurrent	374581000	usd
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	7054000	usd
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	5029000	usd
CY2023Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	120498000	usd
CY2022Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	89578000	usd
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	20455000	usd
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	28933000	usd
CY2023Q4	us-gaap	Assets Current AssetsCurrent	463673000	usd
CY2022Q4	us-gaap	Assets Current AssetsCurrent	636483000	usd
CY2023Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	176608000	usd
CY2022Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	180378000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	55212000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	68440000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	670356000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	670185000	usd
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	62475000	usd
CY2022Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	82900000	usd
CY2023Q4	us-gaap	Marketable Securities Noncurrent MarketableSecuritiesNoncurrent	6088000	usd
CY2022Q4	us-gaap	Marketable Securities Noncurrent MarketableSecuritiesNoncurrent	165105000	usd
CY2023Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	90779000	usd
CY2022Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	92622000	usd
CY2023Q4	us-gaap	Assets Assets	1525191000	usd
CY2022Q4	us-gaap	Assets Assets	1896113000	usd
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	5611000	usd
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	4786000	usd
CY2023Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	61818000	usd
CY2022Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	61161000	usd
CY2023Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	15684000	usd
CY2022Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	28954000	usd
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	24042000	usd
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	23026000	usd
CY2023Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	40539000	usd
CY2022Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	34394000	usd
CY2023Q4	us-gaap	Liabilities Current LiabilitiesCurrent	147694000	usd
CY2022Q4	us-gaap	Liabilities Current LiabilitiesCurrent	152321000	usd
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	343507000	usd
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	704710000	usd
CY2023Q4	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	1602000	usd
CY2022Q4	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	15507000	usd
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	48484000	usd
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	61341000	usd
CY2023Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	4416000	usd
CY2022Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	7076000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	545703000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	940955000	usd
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.00002
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.00002
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	132992126	shares
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	132992126	shares
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	124336171	shares
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	124336171	shares
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	3000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	2000	usd
CY2023Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1815245000	usd
CY2022Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1666106000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1008000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-9286000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-834752000	usd
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-701664000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	979488000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	955158000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1525191000	usd
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1896113000	usd
CY2023	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	505988000	usd
CY2022	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	432725000	usd
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	354330000	usd
CY2023	us-gaap	Cost Of Revenue CostOfRevenue	239660000	usd
CY2022	us-gaap	Cost Of Revenue CostOfRevenue	222944000	usd
CY2021	us-gaap	Cost Of Revenue CostOfRevenue	167002000	usd
CY2023	us-gaap	Gross Profit GrossProfit	266328000	usd
CY2022	us-gaap	Gross Profit GrossProfit	209781000	usd
CY2021	us-gaap	Gross Profit GrossProfit	187328000	usd
CY2023	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	152190000	usd
CY2022	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	155308000	usd
CY2021	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	126859000	usd
CY2023	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	191773000	usd
CY2022	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	179869000	usd
CY2021	us-gaap	Selling And Marketing Expense SellingAndMarketingExpense	152645000	usd
CY2023	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	116077000	usd
CY2022	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	120803000	usd
CY2021	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	126845000	usd
CY2023	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	4316000	usd
CY2022	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2021	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2023	us-gaap	Operating Expenses OperatingExpenses	464356000	usd
CY2022	us-gaap	Operating Expenses OperatingExpenses	455980000	usd
CY2021	us-gaap	Operating Expenses OperatingExpenses	406349000	usd
CY2023	us-gaap	Operating Income Loss OperatingIncomeLoss	-198028000	usd
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	-246199000	usd
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	-219021000	usd
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	52416000	usd
CY2022	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	54391000	usd
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	usd
CY2023	us-gaap	Investment Income Interest InvestmentIncomeInterest	18186000	usd
CY2022	us-gaap	Investment Income Interest InvestmentIncomeInterest	7044000	usd
CY2021	us-gaap	Investment Income Interest InvestmentIncomeInterest	1282000	usd
CY2023	us-gaap	Interest Expense InterestExpense	4051000	usd
CY2022	us-gaap	Interest Expense InterestExpense	5887000	usd
CY2021	us-gaap	Interest Expense InterestExpense	5245000	usd
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	356000	usd
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.03
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.03
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-133088000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	8278000	usd
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-124810000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-197433000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1061865000	usd
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	12626000	usd
CY2021	fsly	Stock Issued During Period Value Vesting Of Early Exercised Stock Options StockIssuedDuringPeriodValueVestingOfEarlyExercisedStockOptions	405000	usd
CY2021	fsly	Stock Sold During Period Value Restricted Stock Award StockSoldDuringPeriodValueRestrictedStockAward	10655000	usd
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	8798000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	144934000	usd
CY2021	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	0	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-222697000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-2633000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	1013953000	usd
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	5688000	usd
CY2022	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	4665000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	128285000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-190774000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-6659000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	955158000	usd
CY2023	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2169000	usd
CY2023	us-gaap	Stock Issued During Period Value Restricted Stock Award Gross StockIssuedDuringPeriodValueRestrictedStockAwardGross	1000	usd
CY2023	fsly	Stock Issued During Period Value Bonus Program StockIssuedDuringPeriodValueBonusProgram	16599000	usd
CY2023	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	8692000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	121679000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-133088000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	8278000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	979488000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-133088000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-190774000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-222697000	usd
CY2023	us-gaap	Depreciation Nonproduction DepreciationNonproduction	51602000	usd
CY2022	us-gaap	Depreciation Nonproduction DepreciationNonproduction	42619000	usd
CY2021	us-gaap	Depreciation Nonproduction DepreciationNonproduction	28799000	usd
CY2023	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	20424000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	21696000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	21238000	usd
CY2023	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	22678000	usd
CY2022	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	25448000	usd
CY2021	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	23065000	usd
CY2023	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	2476000	usd
CY2022	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	3169000	usd
CY2021	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	3185000	usd
CY2023	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	15548000	usd
CY2022	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	8916000	usd
CY2021	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	6294000	usd
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	136303000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	145796000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	140488000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-900000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	0	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	0	usd
CY2023	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2025000	usd
CY2022	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2406000	usd
CY2021	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	196000	usd
CY2023	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-505000	usd
CY2022	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-854000	usd
CY2021	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	300000	usd
CY2023	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	646000	usd
CY2022	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-3137000	usd
CY2021	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-2221000	usd
CY2023	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	744000	usd
CY2022	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	2083000	usd
CY2021	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	0	usd
CY2023	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	4316000	usd
CY2022	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2021	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	52416000	usd
CY2022	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	54391000	usd
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-4000	usd
CY2022	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	27359000	usd
CY2021	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	14563000	usd
CY2023	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-8709000	usd
CY2022	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	6758000	usd
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	4777000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	23137000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	35396000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	10423000	usd
CY2023	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	382000	usd
CY2022	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-4724000	usd
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	146000	usd
CY2023	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-7856000	usd
CY2022	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	8289000	usd
CY2023	fsly	Increase Decrease In Operating Lease Liabilities IncreaseDecreaseInOperatingLeaseLiabilities	-22074000	usd
CY2021	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	928155000	usd
CY2022	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	161918000	usd
CY2021	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	66527000	usd
CY2023	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	433767000	usd
CY2022	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	535040000	usd
CY2021	us-gaap	Proceeds From Sale And Maturity Of Marketable Securities ProceedsFromSaleAndMaturityOfMarketableSecurities	118085000	usd
CY2023	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	usd
CY2022	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	25902000	usd
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	1169000	usd
CY2023	fsly	Advances For Payments Of Property Plant And Equipment AdvancesForPaymentsOfPropertyPlantAndEquipment	0	usd
CY2022	fsly	Advances For Payments Of Property Plant And Equipment AdvancesForPaymentsOfPropertyPlantAndEquipment	42197000	usd
CY2021	fsly	Advances For Payments Of Property Plant And Equipment AdvancesForPaymentsOfPropertyPlantAndEquipment	0	usd
CY2023	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	0	usd
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	10976000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	19975000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	34816000	usd
CY2023	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	49000	usd
CY2022	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	492000	usd
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	588000	usd
CY2023	us-gaap	Payments For Software PaymentsForSoftware	21292000	usd
CY2022	us-gaap	Payments For Software PaymentsForSoftware	18146000	usd
CY2021	us-gaap	Payments For Software PaymentsForSoftware	13479000	usd
CY2022	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	0	usd
CY2021	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	2092000	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	294940000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	235751000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-794511000	usd
CY2023	us-gaap	Proceeds From Convertible Debt ProceedsFromConvertibleDebt	0	usd
CY2022	us-gaap	Proceeds From Convertible Debt ProceedsFromConvertibleDebt	0	usd
CY2021	us-gaap	Proceeds From Convertible Debt ProceedsFromConvertibleDebt	930775000	usd
CY2023	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	usd
CY2022	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	usd
CY2021	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	1351000	usd
CY2023	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	310540000	usd
CY2022	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	177082000	usd
CY2021	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	0	usd
CY2023	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	27175000	usd
CY2022	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	22532000	usd
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	13568000	usd
CY2023	fsly	Proceeds From Early Sale Of Restricted Shares ProceedsFromEarlySaleOfRestrictedShares	0	usd
CY2022	fsly	Proceeds From Early Sale Of Restricted Shares ProceedsFromEarlySaleOfRestrictedShares	10655000	usd
CY2021	fsly	Proceeds From Early Sale Of Restricted Shares ProceedsFromEarlySaleOfRestrictedShares	0	usd
CY2023	fsly	Payments For Early Sale Of Restricted Shares PaymentsForEarlySaleOfRestrictedShares	0	usd
CY2022	fsly	Payments For Early Sale Of Restricted Shares PaymentsForEarlySaleOfRestrictedShares	10655000	usd
CY2021	fsly	Payments For Early Sale Of Restricted Shares PaymentsForEarlySaleOfRestrictedShares	0	usd
CY2023	fsly	Deferred Payment For Business Combinations DeferredPaymentForBusinessCombinations	4393000	usd
CY2022	fsly	Deferred Payment For Business Combinations DeferredPaymentForBusinessCombinations	0	usd
CY2021	fsly	Deferred Payment For Business Combinations DeferredPaymentForBusinessCombinations	0	usd
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2169000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	5688000	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	12626000	usd
CY2023	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	8559000	usd
CY2022	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	4777000	usd
CY2021	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	8069000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-331380000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-189149000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	936551000	usd
CY2023	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	608000	usd
CY2022	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-390000	usd
CY2021	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-477000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-35470000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-23420000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	103081000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	143541000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	166961000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	63880000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	108071000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	143541000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	166961000	usd
CY2023	us-gaap	Interest Paid Net InterestPaidNet	1574000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	2656000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	1938000	usd
CY2023	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	331000	usd
CY2022	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	250000	usd
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	267000	usd
CY2023	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	640000	usd
CY2022	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1492000	usd
CY2021	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	18275000	usd
CY2023	fsly	Vesting Of Early Exercised Stock Options VestingOfEarlyExercisedStockOptions	0	usd
CY2022	fsly	Vesting Of Early Exercised Stock Options VestingOfEarlyExercisedStockOptions	0	usd
CY2021	fsly	Vesting Of Early Exercised Stock Options VestingOfEarlyExercisedStockOptions	405000	usd
CY2023	fsly	Share Based Payment Arrangement Noncash Amount Capitalized Into Internal Use Software ShareBasedPaymentArrangementNoncashAmountCapitalizedIntoInternalUseSoftware	9975000	usd
CY2022	fsly	Share Based Payment Arrangement Noncash Amount Capitalized Into Internal Use Software ShareBasedPaymentArrangementNoncashAmountCapitalizedIntoInternalUseSoftware	7997000	usd
CY2021	fsly	Share Based Payment Arrangement Noncash Amount Capitalized Into Internal Use Software ShareBasedPaymentArrangementNoncashAmountCapitalizedIntoInternalUseSoftware	4446000	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	5769000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	29606000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	32458000	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	23575000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	31529000	usd
CY2023	fsly	Noncash Change In Operating Lease Assets And Liabilities NoncashChangeInOperatingLeaseAssetsAndLiabilities	-4425000	usd
CY2022	fsly	Noncash Change In Operating Lease Assets And Liabilities NoncashChangeInOperatingLeaseAssetsAndLiabilities	3126000	usd
CY2021	fsly	Noncash Change In Operating Lease Assets And Liabilities NoncashChangeInOperatingLeaseAssetsAndLiabilities	0	usd
CY2023	us-gaap	Interest Paid Capitalized InterestPaidCapitalized	1329000	usd
CY2022	us-gaap	Interest Paid Capitalized InterestPaidCapitalized	2381000	usd
CY2021	us-gaap	Interest Paid Capitalized InterestPaidCapitalized	1754000	usd
CY2023	fsly	Payment For Business Incurred But Not Yet Paid PaymentForBusinessIncurredButNotYetPaid	0	usd
CY2022	fsly	Payment For Business Incurred But Not Yet Paid PaymentForBusinessIncurredButNotYetPaid	8000000	usd
CY2021	fsly	Payment For Business Incurred But Not Yet Paid PaymentForBusinessIncurredButNotYetPaid	0	usd
CY2023	fsly	Deployments Of Prepaid Capital Equipment DeploymentsOfPrepaidCapitalEquipment	8665000	usd
CY2022	fsly	Deployments Of Prepaid Capital Equipment DeploymentsOfPrepaidCapitalEquipment	5184000	usd
CY2021	fsly	Deployments Of Prepaid Capital Equipment DeploymentsOfPrepaidCapitalEquipment	0	usd
CY2023	fsly	Receivable Related To Shares Of Restricted Stock ReceivableRelatedToSharesOfRestrictedStock	0	usd
CY2022	fsly	Receivable Related To Shares Of Restricted Stock ReceivableRelatedToSharesOfRestrictedStock	0	usd
CY2021	fsly	Receivable Related To Shares Of Restricted Stock ReceivableRelatedToSharesOfRestrictedStock	10655000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	107921000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	143391000	usd
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	166068000	usd
CY2023Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	150000	usd
CY2022Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	150000	usd
CY2021Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	0	usd
CY2023Q4	us-gaap	Restricted Cash Equivalents RestrictedCashEquivalents	0	usd
CY2022Q4	us-gaap	Restricted Cash Equivalents RestrictedCashEquivalents	0	usd
CY2021Q4	us-gaap	Restricted Cash Equivalents RestrictedCashEquivalents	893000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	108071000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	143541000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	166961000	usd
CY2023	us-gaap	Nature Of Operations NatureOfOperations	Nature of Business<div style="margin-bottom:12pt;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Fastly, Inc. has built an edge cloud platform that can process, serve, and secure its customer’s applications as close to their end users as possible. As of December 31, 2023, the Company’s edge network spans across 79 markets around the world. The Company was incorporated in Delaware in 2011 and is headquartered in San Francisco, California.</span></div><div style="margin-bottom:12pt;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">As used herein,</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%"> “</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Fastly,” “the Company,”</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%"> </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">“its” and similar terms include Fastly, Inc. and its subsidiaries, unless the context indicates otherwise.</span></div><div style="margin-bottom:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Conversion of Dual Class Common Stock Structure</span></div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">On July 12, 2021, all outstanding shares of Class B common stock automatically converted into the same number of shares of Class A common stock (the “Conversion”) pursuant to the terms of the Company’s amended and restated certificate of incorporation (the “Certificate”). Upon the Conversion, outstanding options denominated in shares of Class B common stock issued under any of the Company’s equity incentive plans remained unchanged, except that such options now represent the right to receive shares of Class A common stock on exercise. In accordance with the Certificate, the shares of Class B common stock that converted to Class A common stock were retired and will not be reissued by the Company.</span>
CY2023Q4	fsly	Operating Markets OperatingMarkets	79	operating_market
CY2023	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain changes to presentation have been made to conform the prior period presentation to the current period reporting. The Company has made certain presentation changes to consolidate the interest paid on finance lease line into other liabilities working capital changes and components of the non-cash lease expense related to operating lease liability changes into operating lease liability working capital changes within operating cash flows in the consolidated statements of cash flows. Such reclassifications did not affect the consolidated balance sheets, total revenues, operating income, net income, or cash flows from operating, investing or financing activities.
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-bottom:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates</span></div><div style="margin-bottom:12pt;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets, liabilities, revenue, costs and expenses, and related disclosures. Actual results and outcomes could differ significantly from the Company’s estimates, judgments, and assumptions. Significant estimates, judgments, and assumptions used in these financial statements include, but are not limited to, those related to revenue, accounts receivable and related reserves, internal-use software development costs, the incremental borrowing rate related to the Company’s lease liabilities,</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%"> </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">fair value of assets acquired and liabilities assumed during business combinations, useful lives of acquired intangible assets and property and equipment, fair value of the Company’s long-lived assets as well as reporting unit, income tax reserves, and accounting for stock-based compensation. Estimates are periodically reviewed in light of changes in circumstances, facts, and experience. The effects of material revisions in estimates are reflected in the consolidated financial statements in the period of change and prospectively from the date of the change in estimate.</span></div>
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="margin-bottom:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Concentrations of Credit Risk</span></div><div style="margin-bottom:12pt;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, marketable securities and accounts receivable. </span></div><div style="margin-bottom:12pt;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company’s cash, cash equivalents, and marketable securities primarily consisted of bank deposits, money market funds, investment-grade commercial paper, corporate notes and bonds, U.S. treasury securities, agency bonds, municipal securities, foreign government and supranational securities and asset-backed securities held at major financial institutions that </span></div><div style="margin-bottom:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">the Company believes to be of high credit standing. The primary focus of its investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy limits the amount of credit exposure with any one financial institution or commercial issuer. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheets. While the Company has not experienced any losses in such accounts and the Company has historically maintained its cash in multiple financial institutions, the failure of Silicon Valley Bank (“SVB”) in March 2023, at which the Company held cash and cash equivalents in multiple accounts, exposed the Company to limited credit risk prior to the completion by the Federal Deposit Insurance Corporation (“FDIC”) of the resolution of SVB in a manner that fully protected all depositors.</span></div>Concentrations of credit risk with respect to accounts receivable are primarily limited to certain customers to which the Company makes substantial sales. The Company’s customer base consists of a large number of geographically dispersed customers diversified across several industries
CY2023Q4	us-gaap	Restricted Cash RestrictedCash	200000	usd
CY2022Q4	us-gaap	Restricted Cash RestrictedCash	200000	usd
CY2023	us-gaap	Advertising Expense AdvertisingExpense	4600000	usd
CY2022	us-gaap	Advertising Expense AdvertisingExpense	2500000	usd
CY2021	us-gaap	Advertising Expense AdvertisingExpense	2300000	usd
CY2023Q4	us-gaap	Cash Equivalents At Carrying Value CashEquivalentsAtCarryingValue	86652000	usd
CY2023Q4	us-gaap	Marketable Securities MarketableSecurities	220887000	usd
CY2023	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	505988000	usd
CY2022	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	432725000	usd
CY2021	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	354330000	usd
CY2023Q4	fsly	Enterprise Customer Threshold EnterpriseCustomerThreshold	100000	usd
CY2022Q4	us-gaap	Marketable Securities MarketableSecurities	539686000	usd
CY2023Q4	fsly	Cash Cash Equivalents And Marketable Securities CashCashEquivalentsAndMarketableSecurities	328808000	usd
CY2022Q4	fsly	Cash Cash Equivalents And Marketable Securities CashCashEquivalentsAndMarketableSecurities	683077000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	287307000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	23000	usd
CY2023Q4	fsly	Enterprise Customer Threshold EnterpriseCustomerThreshold	100000	usd
CY2023	us-gaap	Revenue Performance Obligation Description Of Payment Terms RevenuePerformanceObligationDescriptionOfPaymentTerms	The Company’s payment terms and conditions vary by contract type, and generally range from 30 to 90 days.
CY2023Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	621000	usd
CY2022Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	19000	usd
CY2023Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	38150000	usd
CY2022Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	30544000	usd
CY2023	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	28616000	usd
CY2022	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	26274000	usd
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	235700000	usd
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Percentage RevenueRemainingPerformanceObligationPercentage	0.80
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P12M
CY2023Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	61981000	usd
CY2022Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	50523000	usd
CY2023	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	15500000	usd
CY2022	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	8900000	usd
CY2021	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	6300000	usd
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	107921000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	143391000	usd
CY2023Q4	us-gaap	Marketable Securities Current MarketableSecuritiesCurrent	214799000	usd
CY2022Q4	us-gaap	Marketable Securities Current MarketableSecuritiesCurrent	374581000	usd
CY2023Q4	us-gaap	Marketable Securities Noncurrent MarketableSecuritiesNoncurrent	6088000	usd
CY2022Q4	us-gaap	Marketable Securities Noncurrent MarketableSecuritiesNoncurrent	165105000	usd
CY2023Q4	us-gaap	Marketable Securities MarketableSecurities	220887000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	957000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	286373000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	548333000	usd
CY2023Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	150000	usd
CY2023Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	307689000	usd
CY2022Q4	us-gaap	Cash Equivalents At Carrying Value CashEquivalentsAtCarryingValue	96875000	usd
CY2022Q4	us-gaap	Marketable Securities MarketableSecurities	539686000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	0	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	8647000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	539686000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	28	security
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	76	security
CY2022Q4	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	150000	usd
CY2022Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	636711000	usd
CY2022Q4	us-gaap	Restricted Cash RestrictedCash	200000	usd
CY2023Q4	us-gaap	Restricted Cash RestrictedCash	200000	usd
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	5029000	usd
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	3311000	usd
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	3248000	usd
CY2023	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2025000	usd
CY2022	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	2406000	usd
CY2021	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	196000	usd
CY2023	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	0	usd
CY2022	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	688000	usd
CY2021	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	133000	usd
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	7054000	usd
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	5029000	usd
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	3311000	usd
CY2023Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Before Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization	333911000	usd
CY2022Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Before Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization	302839000	usd
CY2023Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization	157303000	usd
CY2022Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization	122461000	usd
CY2023Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	176608000	usd
CY2022Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	180378000	usd
CY2023	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	4300000	usd
CY2021	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2022	fsly	Asset Impairment Charges Excluding Operating Lease Impairment AssetImpairmentChargesExcludingOperatingLeaseImpairment	0	usd
CY2023	us-gaap	Depreciation Depreciation	51600000	usd
CY2022	us-gaap	Depreciation Depreciation	42600000	usd
CY2021	us-gaap	Depreciation Depreciation	28800000	usd
CY2023Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	61981000	usd
CY2022Q4	us-gaap	Capitalized Contract Cost Net Noncurrent CapitalizedContractCostNetNoncurrent	50523000	usd
CY2023Q4	fsly	Advances On Property And Equipment AdvancesOnPropertyAndEquipment	24509000	usd
CY2022Q4	fsly	Advances On Property And Equipment AdvancesOnPropertyAndEquipment	37013000	usd
CY2023Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	4289000	usd
CY2022Q4	us-gaap	Other Assets Miscellaneous Noncurrent OtherAssetsMiscellaneousNoncurrent	5086000	usd
CY2023Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	90779000	usd
CY2022Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	92622000	usd
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	14918000	usd
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	20204000	usd
CY2023Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	24614000	usd
CY2022Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	15818000	usd
CY2023Q4	fsly	Accrued Colocation And Bandwidth Costs AccruedColocationAndBandwidthCosts	14362000	usd
CY2022Q4	fsly	Accrued Colocation And Bandwidth Costs AccruedColocationAndBandwidthCosts	10448000	usd
CY2023Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	4344000	usd
CY2022Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	8698000	usd
CY2023Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	3580000	usd
CY2022Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	5993000	usd
CY2023Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	61818000	usd
CY2022Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	61161000	usd
CY2023Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	33824000	usd
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	28047000	usd
CY2023Q4	fsly	Accrued Computer And Networking Equipment AccruedComputerAndNetworkingEquipment	1673000	usd
CY2022Q4	fsly	Accrued Computer And Networking Equipment AccruedComputerAndNetworkingEquipment	1467000	usd
CY2023Q4	fsly	Business Combination Consideration Transferred Holdback Current BusinessCombinationConsiderationTransferredHoldbackCurrent	3771000	usd
CY2022Q4	fsly	Business Combination Consideration Transferred Holdback Current BusinessCombinationConsiderationTransferredHoldbackCurrent	4013000	usd
CY2023Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	1271000	usd
CY2022Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	867000	usd
CY2023Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	40539000	usd
CY2022Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	34394000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-2633000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-6659000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	8278000	usd
CY2023	us-gaap	Sublease Income SubleaseIncome	1200000	usd
CY2022	us-gaap	Sublease Income SubleaseIncome	900000	usd
CY2021	us-gaap	Sublease Income SubleaseIncome	1000000	usd
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	26996000	usd
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	30976000	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	26716000	usd
CY2023	us-gaap	Variable Lease Cost VariableLeaseCost	15112000	usd
CY2022	us-gaap	Variable Lease Cost VariableLeaseCost	11736000	usd
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	6820000	usd
CY2023	fsly	Operating Variable And Short Term Lease Costs OperatingVariableAndShortTermLeaseCosts	42108000	usd
CY2022	fsly	Operating Variable And Short Term Lease Costs OperatingVariableAndShortTermLeaseCosts	42712000	usd
CY2021	fsly	Operating Variable And Short Term Lease Costs OperatingVariableAndShortTermLeaseCosts	33536000	usd
CY2023	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14391000	usd
CY2022	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14539000	usd
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	6834000	usd
CY2023	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	1328000	usd
CY2022	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	2381000	usd
CY2021	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	1754000	usd
CY2023	fsly	Finance Lease Cost FinanceLeaseCost	15719000	usd
CY2022	fsly	Finance Lease Cost FinanceLeaseCost	16920000	usd
CY2021	fsly	Finance Lease Cost FinanceLeaseCost	8588000	usd
CY2023	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	700000	usd
CY2022	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	2100000	usd
CY2021	us-gaap	Operating Lease Impairment Loss OperatingLeaseImpairmentLoss	0	usd
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P3Y5M23D
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y1M2D
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y4M28D
CY2023Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P1Y
CY2022Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P1Y8M26D
CY2021Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P2Y2M23D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0603
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0536
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0520
CY2023Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0467
CY2022Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0473
CY2021Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0486
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	82900000	usd
CY2023	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	20400000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	21700000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	21200000	usd
CY2023	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	0	usd
CY2021	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	2100000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	28160000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	16064000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	20868000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	1617000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	18896000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	10502000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2446000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	1838000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	82710000	usd
CY2023Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	17681000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	7905000	usd
CY2023Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	395000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	74805000	usd
CY2023Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	17286000	usd
CY2023Q4	fsly	Lessee Operating Lease Lease Not Yet Commenced Commitment Amount LesseeOperatingLeaseLeaseNotYetCommencedCommitmentAmount	2300000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	670185000	usd
CY2021Q4	us-gaap	Goodwill Goodwill	636805000	usd
CY2023	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	usd
CY2022	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	33419000	usd
CY2023	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	171000	usd
CY2022	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-39000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	670356000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	670185000	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2023	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	128884000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	66409000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	62475000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	131084000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	48184000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	19599000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	16976000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	9193000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	9051000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	6891000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	765000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	62475000	usd
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	52400000	usd
CY2023	us-gaap	Interest Expense Debt InterestExpenseDebt	2700000	usd
CY2022	us-gaap	Interest Expense Debt InterestExpenseDebt	3400000	usd
CY2021	us-gaap	Interest Expense Debt InterestExpenseDebt	3500000	usd
CY2023Q4	us-gaap	Notes Payable Fair Value Disclosure NotesPayableFairValueDisclosure	301400000	usd
CY2022Q4	us-gaap	Notes Payable Fair Value Disclosure NotesPayableFairValueDisclosure	517500000	usd
CY2023Q4	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	59179000	usd
CY2023Q4	us-gaap	Purchase Obligation Due In Second Year PurchaseObligationDueInSecondYear	9902000	usd
CY2023Q4	us-gaap	Purchase Obligation Due In Third Year PurchaseObligationDueInThirdYear	10208000	usd
CY2023Q4	us-gaap	Purchase Obligation Due In Fourth Year PurchaseObligationDueInFourthYear	111000	usd
CY2023Q4	us-gaap	Purchase Obligation Due In Fifth Year PurchaseObligationDueInFifthYear	40000	usd
CY2023Q4	us-gaap	Purchase Obligation Due After Fifth Year PurchaseObligationDueAfterFifthYear	0	usd
CY2023Q4	us-gaap	Purchase Obligation PurchaseObligation	79440000	usd
CY2023Q4	fsly	Sales And Excise Tax Payable Current Excluding Normal Activity SalesAndExciseTaxPayableCurrentExcludingNormalActivity	4300000	usd
CY2022Q4	fsly	Sales And Excise Tax Payable Current Excluding Normal Activity SalesAndExciseTaxPayableCurrentExcludingNormalActivity	7600000	usd
CY2023	fsly	Number Of Equity Incentive Plans NumberOfEquityIncentivePlans	4	plan
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2443000	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	6.01
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P4Y8M12D
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	7674000	usd
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	602000	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	16.47
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	291000	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	7.45
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod	44000	shares
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice	8.41
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2710000	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.14
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P5Y1M6D
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	26383000	usd
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber	2142000	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice	5.94
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1	P3Y9M18D
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue	25620000	usd
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	3100000	usd
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	8900000	usd
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	64900000	usd
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	2100000	usd
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	5600000	usd
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	6900000	usd
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	10.97
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions	6200000	usd
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	136303000	usd
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	145796000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	140488000	usd
CY2023	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	10100000	usd
CY2022	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	8000000	usd
CY2021	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	4400000	usd
CY2023	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	21509000	shares
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	26175000	shares
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	19341000	shares
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-137240000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-196469000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-224159000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	3931000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	5789000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	1531000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-133309000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-190680000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-222628000	usd
CY2023	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	usd
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	usd
CY2023	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	57000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-79000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	usd
CY2023	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	622000	usd
CY2022	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	173000	usd
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	322000	usd
CY2023	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	0	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	0	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-253000	usd
CY2023	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	usd
CY2023	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-900000	usd
CY2022	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	usd
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-221000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	94000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	69000	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.25
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.14
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.30
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.01
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.04
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.09
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.02
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	0.10
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	0.02
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	0.05
CY2023	fsly	Effective Income Tax Rate Reconciliation Nondeductible Expense Disallowed Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDisallowedExecutiveCompensationPercent	-0.03
CY2022	fsly	Effective Income Tax Rate Reconciliation Nondeductible Expense Disallowed Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDisallowedExecutiveCompensationPercent	0
CY2021	fsly	Effective Income Tax Rate Reconciliation Nondeductible Expense Disallowed Executive Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDisallowedExecutiveCompensationPercent	0
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Restructuring Charges EffectiveIncomeTaxRateReconciliationNondeductibleExpenseRestructuringCharges	0
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Restructuring Charges EffectiveIncomeTaxRateReconciliationNondeductibleExpenseRestructuringCharges	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Restructuring Charges EffectiveIncomeTaxRateReconciliationNondeductibleExpenseRestructuringCharges	0.02
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-200000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	100000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	100000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	178149000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	183306000	usd
CY2023Q4	fsly	Deferred Tax Asset Lease Liability DeferredTaxAssetLeaseLiability	20137000	usd
CY2022Q4	fsly	Deferred Tax Asset Lease Liability DeferredTaxAssetLeaseLiability	23245000	usd
CY2023Q4	us-gaap	Deferred Tax Assets In Process Research And Development DeferredTaxAssetsInProcessResearchAndDevelopment	38280000	usd
CY2022Q4	us-gaap	Deferred Tax Assets In Process Research And Development DeferredTaxAssetsInProcessResearchAndDevelopment	21383000	usd
CY2023Q4	fsly	Deferred Tax Assets Capitalized Research And Development Costs DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts	45418000	usd
CY2022Q4	fsly	Deferred Tax Assets Capitalized Research And Development Costs DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts	21032000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	11765000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	10429000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	4934000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	2811000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	4336000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	4648000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1889000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	4179000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	304908000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	271033000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	16310000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	21713000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	15322000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	18847000	usd
CY2023Q4	fsly	Deferred Tax Liabilities State Taxes DeferredTaxLiabilitiesStateTaxes	13032000	usd
CY2022Q4	fsly	Deferred Tax Liabilities State Taxes DeferredTaxLiabilitiesStateTaxes	10732000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	13868000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	11526000	usd
CY2023Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	58532000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	62818000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	245476000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	208215000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	900000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	0	usd
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	37300000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	17337000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	7808000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	2674000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	8697000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	751000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3234000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1583000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	23245000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	17337000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	23200000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	17300000	usd
CY2023Q4	fsly	Property Plant And Equipment Net And Operating Lease Right Of Use Assets Net PropertyPlantAndEquipmentNetAndOperatingLeaseRightOfUseAssetsNet	231820000	usd
CY2022Q4	fsly	Property Plant And Equipment Net And Operating Lease Right Of Use Assets Net PropertyPlantAndEquipmentNetAndOperatingLeaseRightOfUseAssetsNet	248818000	usd
CY2023Q4	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false

Files In Submission

Name	View Source	Status
0001517413-24-000048-index-headers.html	Edgar Link	pending
0001517413-24-000048-index.html	Edgar Link	pending
0001517413-24-000048.txt	Edgar Link	pending
0001517413-24-000048-xbrl.zip	Edgar Link	pending
ex1014non-employeedirector.htm	Edgar Link	pending
ex971incentivecompensation.htm	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
fsly-123123x10kex211.htm	Edgar Link	pending
fsly-123123x10kex231.htm	Edgar Link	pending
fsly-123123x10kex311.htm	Edgar Link	pending
fsly-123123x10kex312.htm	Edgar Link	pending
fsly-123123x10kex321.htm	Edgar Link	pending
fsly-123123x10kex322.htm	Edgar Link	pending
fsly-20231231.htm	Edgar Link	pending
fsly-20231231.xsd	Edgar Link	pending
fsly-20231231_g1.jpg	Edgar Link	pending
fsly-20231231_g2.jpg	Edgar Link	pending
fsly-20231231_g3.jpg	Edgar Link	pending
fsly-20231231_g4.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
fsly-20231231_def.xml	Edgar Link	unprocessable
fsly-20231231_lab.xml	Edgar Link	unprocessable
fsly-20231231_pre.xml	Edgar Link	unprocessable
fsly-20231231_htm.xml	Edgar Link	completed
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
secondamendmenttocreditagr.htm	Edgar Link	pending
Show.js	Edgar Link	pending
fsly-20231231_cal.xml	Edgar Link	unprocessable

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$FSLY
Fastly, Inc. Stock $fsly

2024 Q1 Form 10-K Financial Statement

#000151741324000048 Filed on February 22, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FSLY Fastly, Inc. Stock $fsly

2024 Q1 Form 10-K Financial Statement

#000151741324000048 Filed on February 22, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FSLY
Fastly, Inc. Stock $fsly