COVER - shares	9 Months Ended
	Sep. 30, 2021	Nov. 11, 2021
Document Information [Line Items]
Document Type	10-Q/A
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-39463
Entity Registrant Name	Ouster, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-2528989
Entity Address, Address Line One	350 Treat Avenue
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94110
City Area Code	415
Local Phone Number	949-0108
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		171,604,276
Amendment Flag	true
Entity Central Index Key	0001816581
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Amendment Description	EXPLANATORY NOTEThis Amendment No. 1 on Form 10-Q/A is being filed solely for the purpose of amending the Section 906 certification (filed herein as Exhibit 32.1 and 32.2) which was originally included with our Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2021, filed with the Securities & Exchange Commission on November 12, 2021 (the “Original Form 10-Q”). The certification included with the Original Form 10-Q contained a typographical error. The corrected certification is being filed with this Form 10-Q/A.Items included in the Original Form 10-Q that are not amended by this Form 10-Q/A remain in effect as of the date of the Original Form 10-Q. This amendment does not reflect events occurring after the filing of the Form 10-Q, or modify or update those disclosures that may be affected by subsequent events, and no other changes are being made to any other disclosure contained in the Form 10-Q.
Common stock, $0.0001 par value per share
Document Information [Line Items]
Title of 12(b) Security	Common stock, $0.0001 par value per share
Trading Symbol	OUST
Security Exchange Name	NYSE
Warrants to purchase common stock
Document Information [Line Items]
Title of 12(b) Security	Warrants to purchase common stock
Trading Symbol	OUST WS
Security Exchange Name	NYSE