Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2025	Mar. 27, 2026	Apr. 30, 2025
Cover [Abstract]
Entity Registrant Name	374WATER INC.
Entity Central Index Key	0000933972
Document Type	10-K/A
Amendment Flag	true
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	No
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Dec. 31, 2025
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2026
Entity Common Stock Shares Outstanding		17,441,368
Entity Public Float			$ 27.4
Document Annual Report	true
Document Transition Report	false
Entity File Number	000-27866
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	88-0271109
Entity Address Address Line 1	100 Southcenter Court
Entity Address Address Line 2	Suite 200
Entity Address City Or Town	Morrisville
Entity Address State Or Province	NC
Entity Address Postal Zip Code	27560
City Area Code	440
Local Phone Number	601-9677
Security 12b Title	Common Stock, $0.0001 par value
Trading Symbol	SCWO
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Document Fin Stmt Error Correction Flag	false
Amendment Description	On March 31, 2026, 374Water Inc. (the “Company”) filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (the “Original Form 10-K”). This Amendment No. 1 (the “Amendment”) amends Part III, Items 10 through 14 of the Original Form 10-K to include information previously omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K, which provides that registrants may incorporate by reference certain information from a definitive proxy statement which involves the election of directors if such definitive proxy statement is filed with the Securities and Exchange Commission (the “SEC”) within 120 days after the end of the fiscal year. The Company is filing this Amendment to include Part III information in its Original Form 10-K because the Company will not file a definitive proxy statement containing this information before that date. The reference on the cover of the Original Form 10-K to the incorporation by reference to portions of the Company’s definitive proxy statement into Part III is hereby deleted. Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), this Amendment also contains new certifications by the principal executive officer and the principal financial officer as required by Section 302 of the Sarbanes-Oxley Act of 2002. Because no financial statements are included in this Amendment and this Amendment does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. Except for the addition of the Part III information, the update to the cover page, and the filing of related certifications, this Amendment does not amend or otherwise update any other information in the Original Form 10-K. Accordingly, this Amendment should be read in conjunction with the Original Form 10-K. Except as specifically stated herein, this Amendment does not reflect events occurring after the filing of the Original Form 10-K and no attempt has been made in this Amendment to modify or update other disclosures as presented in the Original Form 10-K.

374Water Inc. 10-K/A