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v3.25.3

Cover | 9 Months Ended
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Sep. 30, 2025
Cover [Abstract] |
Document Type | S-1/A
Amendment Flag | true
Amendment Description | Client made date edits
Entity Registrant Name | FOCUS UNIVERSAL INC.
Entity Central Index Key | 0001590418
Entity Tax Identification Number | 46-3355876
Entity Incorporation, State or Country Code | NV
Entity Address, Address Line One | 2311 East Locust Court
Entity Address, City or Town | Ontario
Entity Address, State or Province | CA
Entity Address, Postal Zip Code | 91761
City Area Code | 626
Local Phone Number | 272-3883
Entity Filer Category | Non-accelerated Filer
Entity Small Business | true
Entity Emerging Growth Company | false

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