Cover - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Mar. 30, 2025	Jun. 30, 2024
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2024
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2024
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, $0.001 par value
Trading Symbol	FSI
Security Exchange Name	NYSEAMER
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				$ 19,992,921
Entity Common Stock, Shares Outstanding			12,647,532
Documents Incorporated by Reference [Text Block]	None
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Auditor Firm ID	444	995
Auditor Opinion [Text Block]	We have audited the accompanying consolidated balance sheet of Flexible Solutions International Inc. (“the Company”) as of December 31, 2024 and the related consolidated statements of income and comprehensive income, stockholders’ equity and cash flows for the year then ended, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and the results of its operations and its cash flows for the year then ended, in conformity with accounting principles generally accepted in the United States of America.
Auditor Name	Assure CPA, LLC	SMYTHE LLP
Auditor Location	Spokane, Washington	Vancouver, Canada