v3.26.1
Cover - shares
6 Months Ended
Jun. 30, 2026
Aug. 03, 2026
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --12-31  
Entity File Number 001-40544  
Entity Registrant Name Jade Biosciences, Inc.  
Entity Central Index Key 0001798749  
Entity Tax Identification Number 83-1377888  
Entity Incorporation, State or Country Code NV  
Entity Address, Address Line One 221 Crescent Street  
Entity Address, Address Line Two Building 23  
Entity Address, Address Line Three Suite 105  
Entity Address, City or Town Waltham  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02453  
City Area Code 781  
Local Phone Number 312-3013  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol JBIO  
Security Exchange Name NASDAQ  
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  
Elected Not To Use the Extended Transition Period true  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   63,597,387