Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
3 Months Ended
Mar. 31, 2021
Aug. 09, 2021
Cover [Abstract]    
Entity Registrant Name QS Energy, Inc.  
Entity Central Index Key 0001103795  
Document Type 10-Q  
Document Period End Date Mar. 31, 2021  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Is Entity's Reporting Status Current? No  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   345,865,564
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2021  
Entity Small Business true  
Entity Emerging Growth false  
Entity Interactive Data Current No  
Entity Incorporation State Country Code NV  
Entity File Number 0-29185  
Entity Shell Company false