Delta Chat vs Kontalk
Delta Chat
delta.chat
Kontalk
kontalk.orgSide by side
| Figure | Delta Chat | Kontalk |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| iOS | Yes | — |
| Android | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 1 |
| Spec score · Encrypted Messaging Apps | 8.3 (#4) | 7.2 (#34) |
| Spec score · Secure Messaging Apps | 8.2 (#11) | 7.3 (#31) |
| Encryption | All messages are end-to-end encrypted by default, and attachments and their metadata are included in the encryption. | The site says client-to-server and server-to-server channels are fully encrypted, and servers cannot decrypt end-to-end encrypted messages. |
| Platforms | The download page lists Android, iPhone/iPad, macOS, Windows, GNU/Linux, and a community-driven Ubuntu Touch effort. | The network site says Kontalk is available for Android and desktop. |
| Product | Delta Chat is a reliable, decentralized and secure instant messaging app for mobile and desktop. | Kontalk is a community-driven instant messaging network designed for smartphones and tablets. |
| Support | The site links to a Delta Chat forum for support and feedback. | The project links users to a help wiki and a community forum for discussion. |
Plans
In their own words
Delta Chat
Delta Chat is a free, open-source instant messaging app for mobile and desktop, with support for self-hosting. It runs on Android, iOS, Linux, macOS and Windows, and supports multiple profiles and devices. Messages travel through secure, interoperable chatmail relays and are end-to-end encrypted by default, including attachments and their metadata. Delta Chat uses a subset of OpenPGP with Secure-Join and Autocrypt. Servers can still see sender and receiver addresses and message size; other message, contact and group metadata is encrypted. Chats can include interactive web apps for gaming and collaboration. Android and iOS audio and video calls use peer-to-peer WebRTC, but a March 2026 post said the feature was still behind a debug setting. A classic email address can act as a relay only if used exclusively by chatmail clients, and classic email providers generally do not support push notifications. The FAQ says there are no immediate plans for a web client. The project links to a forum for support and feedback.