v3.26.1
Document and Entity Information
 3 Months Ended
Mar. 31, 2026
Document and Entity Information [Abstract]  
Document Type 10-Q
Amendment Flag false
Document Fiscal Period Focus Q1
Document Quarterly Report true
Document Period End Date Mar. 31, 2026
Document Transition Report false
Securities Act File Number 001-40925
Entity Registrant Name Xilio Therapeutics, Inc.
Entity Incorporation, State or Country Code DE
Entity Tax Identification Number 85-1623397
Entity Address, Address Line One 828 Winter Street
Entity Address, Address Line Two Suite 300
Entity Address, City or Town Waltham
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02451
City Area Code 857
Local Phone Number 524-2466
Title of 12(b) Security Common stock, par value $0.0001 per share
Trading Symbol XLO
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 Central Index Key 0001840233
Current Fiscal Year End Date --12-31
Document Fiscal Year Focus 2026