Cover - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Mar. 04, 2026
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-42932
Registrant Name	BETA Technologies, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	83-1276474
Entity Address, Address Line One	1150 Airport Drive
Entity Address, City or Town	South Burlington
Entity Address, State or Province	VT
Entity Address, Postal Zip Code	05403
City Area Code	802
Local Phone Number	281-3623
Title of 12(b) Security	Class A common stock, par value $0.0001
Trading Symbol	BETA
Security Exchange Name	NYSE
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	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Documents Incorporated by Reference	roxy Statement related to the 2026 Annual Meeting of Stockholders are incorporated by reference in Part III of this Annual Report on Form 10-K. This Proxy Statement will be filed with the Securities and Exchange Commission within 120 days after the close of the fiscal year covered by this report.
Central Index Key	0001784570
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2025
Entity Public Float	$ 0
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		221,249,271
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		8,501,484