v3.25.2
Cover - shares
 6 Months Ended
Jun. 30, 2025
Aug. 13, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-40034  
Entity Registrant Name GRI BIO, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 82-4369909  
Entity Address, Address Line One 2223 Avenida de la Playa  
Entity Address, Address Line Two #208  
Entity Address, City or Town La Jolla  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92037  
City Area Code 619  
Local Phone Number 400-1170  
Title of 12(b) Security Common Stock, par value $0.0001per share  
Trading Symbol GRI  
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  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   2,515,305
Entity Central Index Key 0001824293  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false