Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Mar. 08, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2020    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Trading Symbol KZR    
Entity Registrant Name Kezar Life Sciences, Inc.    
Entity Central Index Key 0001645666    
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 true    
Entity Ex Transition Period true    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   48,066,343  
Entity Public Float     $ 174
Entity Interactive Data Current Yes    
Entity File Number 001-38542    
Entity Tax Identification Number 47-3366145    
Entity Address, Address Line One 4000 Shoreline Court    
Entity Address, Address Line Two Suite 300    
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 822-5600    
Document Annual Report true    
Document Transition Report false    
ICFR Auditor Attestation Flag false    
Title of 12(b) Security Common Stock, $0.001 par value    
Security Exchange Name NASDAQ    
Entity Incorporation, State or Country Code DE    
Documents Incorporated by Reference


Portions of the definitive proxy statement for the 2021 Annual Meeting of Stockholders of the registrant, or the Proxy Statement, are incorporated by reference into Part III of this Annual Report on Form 10-K. The Proxy Statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2020.