Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 29, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Registrant Name	RELAY THERAPEUTICS, INC.
Entity Central Index Key	0001812364
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Address, State or Province	MA
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	RLAY
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		108,898,083
Entity File Number	001-39385
Entity Tax Identification Number	47-3923475
Entity Address Address Line1	399 Binney Street
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	370-8837