Cover - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 29, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K/A
Amendment Flag	true
Amendment Description	The purpose of the amendment is to correct Exhibit 23.1
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
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, 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, $0.001 par value
Trading Symbol	FSI
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	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 30,491,533
Entity Common Stock, Shares Outstanding		12,375,746
ICFR Auditor Attestation Flag	false
Auditor Name	Smythe LLP
Auditor Firm ID	995
Auditor Location	Vancouver, Canada