BitChat vs Delta Chat
BitChat
bitchat.free
Delta Chat
delta.chatSide by side
| Figure | BitChat | Delta Chat |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Windows | — | Yes |
| macOS | Yes | Yes |
| Linux | — | Yes |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 1 |
| Spec score · Encrypted Messaging Apps | 8.9 (#1) | 8.3 (#4) |
| Encryption | The project describes Noise Protocol end-to-end encryption for mesh messages and BitChat private envelopes for Nostr fallback messages. | All messages are end-to-end encrypted by default, and attachments and their metadata are included in the encryption. |
| Integrations | The listed internet messaging transport is the Nostr protocol, which connects BitChat users through relays. | Delta Chat supports chatmail relays and in-chat web apps, and can use a classic email address as a relay with limitations. |
| Platforms | The maker's site lists iOS, macOS, and Android builds; iOS requires version 16.0 or later, macOS 13.0 or later, and Android 8.0 or later. | The download page lists Android, iPhone/iPad, macOS, Windows, GNU/Linux, and a community-driven Ubuntu Touch effort. |
Plans
In their own words
BitChat
BitChat is a decentralized messaging app that uses Bluetooth mesh for nearby communication and Nostr relays for internet messaging. Bluetooth messages can pass between nearby devices across as many as seven hops without internet access. When Bluetooth is unavailable, the app can use Nostr; if neither route is available, messages can wait in a queue. Geographic chat rooms use geohash coordinates.
The app requires no account, phone number, or central server. Live mesh sessions use Noise XX for mutual authentication and forward secrecy, while private Nostr messages use an app-specific encrypted format that works only with BitChat clients. However, mesh announcements expose static keys and nicknames in cleartext, and a persistent per-device identifier can allow nearby listeners to follow a device over time and place. A triple-tap emergency wipe clears app data, including identity keys and queued messages. Android adds Wi-Fi Aware on supported devices and built-in Tor. BitChat is available for iOS, Android, and macOS, and is free.
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.