v3.26.1
Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 27, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Current Fiscal Year End Date --12-31    
Entity File Number 0-29185    
Entity Registrant Name QS ENERGY, INC.    
Entity Central Index Key 0001103795    
Entity Tax Identification Number 52-2088326    
Entity Incorporation, State or Country Code NV    
Entity Address, Address Line One 23902 FM 2978    
Entity Address, City or Town Tomball    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 77375    
City Area Code 775    
Local Phone Number 300-7647    
Title of 12(g) Security Common Stock, $0.001 par value    
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     $ 100,504,000
Entity Common Stock, Shares Outstanding   550,617,942  
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Insider Trading Policies and Procedures Adopted [Flag] true    
Auditor Firm ID 572    
Auditor Name Weinberg & Company, P.A.    
Auditor Location Los Angeles, California