Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2024	Mar. 06, 2025	Jun. 30, 2024
Cover [Abstract]
Document Type	10-K/A
Amendment Flag	true
Amendment Description	Explanatory Note On March 7, 2025, Unity Biotechnology, Inc. filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2024 (“Original Form 10-K”). The Original Form 10-K omitted portions of Part III, Items 10 (Directors, Executive Officers and Corporate Governance), 11 (Executive Compensation), 12 (Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters), 13 (Certain Relationships and Related Transactions, and Director Independence), and 14 (Principal Accountant Fees and Services) in reliance on General Instruction G(3) to Form 10-K, which provides that such information may be either incorporated by reference from the registrant’s definitive proxy statement or included in an amendment to Form 10-K, in either case filed with the Securities and Exchange Commission (“SEC”) not later than 120 days after the end of the fiscal year. Due to the timing of our anticipated 36-week data from the ASPIRE study in the second quarter of 2025 and related strategic considerations, we are opting for this filing this Amendment No. 1 to Form 10-K (“Amendment”) to: •amend and restate Part III, Items 10, 11, 12, 13, and 14 of the Original Form 10-K to include the information required by such Items; •delete the reference on the cover of the Original Form 10-K to the incorporation by reference of portions of our proxy statement into Part III of the Original Form 10-K; and •file new certifications of our principal executive officer and principal financial officer as exhibits to this Amendment under Item 15 of Part IV hereof, pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (“Exchange Act”). Because no financial statements are contained within this Amendment, we are not including certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. This Amendment does not otherwise change or update any of the disclosures set forth in the Original Form 10-K and does not otherwise reflect any events occurring after the filing of the Original Form 10-K. Accordingly, the Amendment should be read in conjunction with the Original Form 10-K and the Company’s filings made with the SEC subsequent to the filing of the Original Form 10-K. Capitalized terms used herein and not otherwise defined are defined as set forth in the Original Form 10-K. As used in this report, unless otherwise stated or the context otherwise requires: “we,” “us,” “our,” “Unity,” the “Company,” and similar references refer to Unity Biotechnology, Inc.
Document Period End Date	Dec. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Entity Registrant Name	Unity Biotechnology, Inc.
Entity Central Index Key	0001463361
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		16,867,647
Entity Public Float			$ 22,509,406
Entity File Number	001-38470
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-4726035
Entity Address, Address Line One	285 East Grand Ave.
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	416-1192
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Title of 12(b) Security	Common Stock, par value $0.0001
Security Exchange Name	NASDAQ
Trading Symbol	UBX
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE None.
Document Financial Statement Error Correction [Flag]	false

Unity Biotechnology, Inc. 10-K/A