v3.26.1
Cover
Apr. 28, 2026
Cover [Abstract]  
Document Type S-1/A
Amendment Flag false
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 1515 W. Cameron Ave.
Entity Address, Address Line Two Ste 210
Entity Address, City or Town West Covina
Entity Address, State or Province CA
Entity Address, Postal Zip Code 91790
City Area Code 626
Local Phone Number 272-3883
Entity Filer Category Non-accelerated Filer
Entity Small Business true
Entity Emerging Growth Company false