Delta Chat vs OMEMO Chat
Delta Chat
delta.chat
OMEMO Chat
omemo.globalSide by side
| Figure | Delta Chat | OMEMO Chat |
|---|---|---|
| Price from | Free | — |
| Free plan | Yes | — |
| Free trial | — | Yes |
| 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 (#35) |
| Encryption | All messages are end-to-end encrypted by default, and attachments and their metadata are included in the encryption. | The site describes a hybrid post-quantum key exchange using X25519 and ML-KEM-1024. |
| Messaging | The app supports multi-profile and multi-device use, and relays messages through secure, interoperable chatmail relays. | OMEMO Chat is an open-source client using the OMEMO end-to-end encryption protocol for messages, calls, and shared files. |
| Product | Delta Chat is a reliable, decentralized and secure instant messaging app for mobile and desktop. | OMEMO.global bundles a global data eSIM with a lifetime install of the OMEMO secure-messaging app. |
| Support | The site links to a Delta Chat forum for support and feedback. | The FAQ says email or encrypted chat reaches the same person and receives a reply within a day. |
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.
OMEMO Chat
OMEMO Chat has no write-up on Specifiction yet; its figures are above.