v3.26.1
Document and Entity Information
Mar. 30, 2026
Document And Entity Information [Line Items]  
Amendment Flag false
Entity Central Index Key 0001645666
Document Type 8-K
Document Period End Date Mar. 30, 2026
Entity Registrant Name Kezar Life Sciences, Inc.
Entity Incorporation State Country Code DE
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
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Common Stock [Member]  
Document And Entity Information [Line Items]  
Security 12b Title Common Stock, $0.001 par value per share
Trading Symbol KZR
Security Exchange Name NASDAQ
Preferred Stock [Member]  
Document And Entity Information [Line Items]  
Security 12b Title Preferred Share Purchase Rights
Security Exchange Name NASDAQ