Letterhead vs Substack
| Letterhead | Substack | |
|---|---|---|
| Free plan | No | No |
| Free trial | No | No |
| Paid from | — | — |
| Open source | No | No |
| Platforms | Web | Web, iOS, Android |
| Newsletter website | Yes | — |
| Custom domain | Yes | — |
| API access | Yes | — |
| Free plan | — | Yes |
Both are listed in Best Newsletter Platforms. On Samsung Mobile US Press, Substack scores higher on our published basis.