Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 30, 2022
Cover [Abstract]
Entity Registrant Name	FTC SOLAR, INC.
Entity Central Index Key	0001828161
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Trading Symbol	FTCI
Amendment Flag	false
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ
Entity File Number	001-40350
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4816270
Entity Address, Address Line One	9020 N Capital of Texas Hwy
Entity Address, Address Line Two	Suite I-260
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78759
City Area Code	737
Local Phone Number	787-7906
Entity Common Stock, Shares Outstanding		99,810,544
Document Quarterly Report	true
Document Transition Report	false