otr.to vs Viber
| otr.to | Viber | |
|---|---|---|
| Free plan | No | Yes |
| Free trial | No | No |
| Paid from | — | Free |
| Open source | No | No |
| Platforms | Web | Android, iOS, Linux, macOS, Windows |
| Free plan | — | Yes |
| Account requirement | — | phone |
| Encrypted backups | — | No |
| Desktop apps | — | Yes |
| Maximum group size | — | 250 members |
| Multi-device support | — | Yes |
| Disappearing messages | — | Yes |
Both are listed in Best Secure Messaging Apps. On Freedom251, Viber scores higher on our published basis.