Cover Page - shares	3 Months Ended
	Mar. 31, 2022	May 17, 2022
Cover
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-39331
Entity Registrant Name	System1, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-1531250
Entity Address, Address Line One	4235 Redwood Avenue
Entity Address, City or Town	Marina Del Rey
Entity Address State Or Province	CA
Entity Address, Postal Zip Code	90066
City Area Code	310
Local Phone Number	924-6037
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		90,566,172
Entity Central Index Key	0001805833
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A Common Stock
Cover
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	SST
Security Exchange Name	NYSE
Redeemable warrants, each whole warrant exercisable for one Class A common stock at an exercise price of $11.50 per share
Cover
Title of 12(b) Security	Redeemable warrants, each whole warrant exercisable for one Class A common stock at an exercise price of $11.50 per share
Trading Symbol	SST.WS
Security Exchange Name	NYSE