Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Mar. 12, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	1-11460
Entity Registrant Name	Eterna Therapeutics Inc.
Entity Central Index Key	0000748592
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	31-1103425
Entity Address, Address Line One	1035 Cambridge Street, Suite 18A,
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02141
City Area Code	212
Local Phone Number	582-1199
Title of 12(b) Security	Common Stock, $0.005 par value
Trading Symbol	ERNA
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 9.7
Entity Common Stock, Shares Outstanding		5,410,331
Auditor Firm ID	248
Auditor Name	GRANT THORNTON LLP
Auditor Location	New York, New York