Composer AI vs Kerna
| Composer AI | Kerna | |
|---|---|---|
| Free plan | No | Yes |
| Free trial | No | No |
| Paid from | — | €12/mo |
| Open source | No | No |
| Platforms | Web | macOS, Web, Windows |
| Free plan | Yes | Yes |
| Email context input | thread | thread |
| Browser extension | Yes | No |
| Mail client support | gmail | both |
| Tone controls | — | Yes |
| Custom instructions | — | Yes |
| Supported languages | — | 45 languages |
Both are listed in Best AI Email Writing Tools. On Specifiction, Kerna scores higher on our published basis.