Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 03, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	IN8BIO, INC.
Entity Central Index Key	0001740279
Entity Tax Identification Number	82-5462585
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity File Number	001-39692
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	350 5th Avenue
Entity Address, Address Line Two	Suite 5330
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10118
City Area Code	646
Local Phone Number	600-6438
Trading Symbol	INAB
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		18,754,553
Document Quarterly Report	true
Document Transition Report	false