Cover - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 28, 2022	Nov. 11, 2021
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-41026
Entity Registrant Name	BACKBLAZE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8893125
Entity Address, State or Province	CA
Entity Address, City or Town	San Mateo
Entity Address, Address Line One	500 Ben Franklin Ct
Entity Address, Postal Zip Code	94401
City Area Code	650
Local Phone Number	352-3738
Title of 12(b) Security	Class A Common Stock, $0.0001 par value per share
Trading Symbol	BLZE
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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 Public Float			$ 140.0
Documents Incorporated by Reference	Portions of the information called for by Part III of this Annual Report on Form 10-K is hereby incorporated by reference from the definitive proxy statement for the Registrant’s 2022 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2021.
Entity Central Index Key	0001462056
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Class A common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		8.5
Class B common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		22.1