Cover - shares	3 Months Ended
	Mar. 31, 2025	May 15, 2025
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2025
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2025
Current Fiscal Year End Date	--12-31
Entity File Number	001-31540
Entity Registrant Name	FLEXIBLE SOLUTIONS INTERNATIONAL INC.
Entity Central Index Key	0001069394
Entity Tax Identification Number	71-1630889
Entity Incorporation, State or Country Code	A0
Entity Address, Address Line One	6001 54 Ave.
Entity Address, City or Town	Taber
Entity Address, State or Province	AB
Entity Address, Country	CA
Entity Address, Postal Zip Code	T1G 1X4
City Area Code	(403)
Local Phone Number	223-2995
Title of 12(b) Security	Common Stock
Trading Symbol	FSI
Security Exchange Name	NYSEAMER
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		12,647,532