Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2025	Feb. 28, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	001-42790
Registrant Name	Heartflow, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-0506743
Entity Address, Address Line One	331 E. Evelyn Avenue
Entity Address, City or Town	Mountain View
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94041
City Area Code	650
Local Phone Number	241-1221
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	HTFL
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	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		85,757,754
Documents Incorporated by Reference [Text Block]	Portions of the registrant’s definitive proxy statement relating to the registrant’s 2026 Annual Meeting of Stockholders, to be filed within 120 days of the registrant’s fiscal year ended December 31, 2025, are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated.
Auditor Firm ID	238
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	San Jose, California
Entity Central Index Key	0001464521
Amendment Flag	false