Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Oct. 03, 2023
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Trading Symbol	TCRX
Entity Registrant Name	TSCAN THERAPEUTICS, INC.
Entity Central Index Key	0001783328
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-40603
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-5282075
Entity Address, Address Line One	830 Winter Street
Entity Address, State or Province	MA
Entity Address, City or Town	Waltham
Entity Address, Postal Zip Code	02451
City Area Code	857
Local Phone Number	399-9500
Title of 12(b) Security	Voting Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Voting Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		43,548,092
Non-voting Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		4,276,588