| Document and Entity Information | Sep. 23, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | SONIM TECHNOLOGIES INC |
| Amendment Flag | false |
| Entity Central Index Key | 0001178697 |
| Document Type | 8-K |
| Document Period End Date | Sep. 23, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38907 |
| Entity Tax Identification Number | 94-3336783 |
| Entity Address, Address Line One | 6500 River Place Boulevard |
| Entity Address, Address Line Two | Building 7 |
| Entity Address, Address Line Three | Suite 250 |
| Entity Address, City or Town | Austin |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78730 |
| City Area Code | (650) |
| Local Phone Number | 378-8100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.001 per share |
| Trading Symbol | SONM |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
