BitChat

BitChat is a peer-to-peer messaging app for nearby Bluetooth mesh communication and internet messaging through Nostr relays. Nearby devices can relay messages over Bluetooth without internet, across as many as seven hops. The app prefers Bluetooth when available, can switch to Nostr, and can queue messages when neither route is available. Geographic chat rooms use geohash coordinates. BitChat requires no account, phone number, or central server. Its whitepaper says live mesh sessions use Noise XX for mutual authentication and forward secrecy, while Nostr private messages use an app-specific encrypted format that works only between BitChat clients. Mesh announcements also expose static keys and nicknames in cleartext, which can let a nearby listener follow a device across time and places. A triple-tap emergency wipe clears app data, including identity keys and queued messages. Android supports Wi-Fi Aware on compatible devices and built-in Tor. BitChat is listed for iOS, Android, and macOS; Android APK releases are also available through GitHub. The maker describes offline mesh communication as useful during internet outages, natural disasters, protests, and in areas with limited connectivity.

BitChat provides nearby offline mesh messaging and internet messaging through Nostr, with automatic routing and message queuing. Its mesh announcements expose identifying details to nearby listeners, and its Nostr private-message format is limited to BitChat clients.

BitChat suits people who need nearby messaging when internet access is limited or unavailable. Its Nostr private-message format works only between BitChat clients.

BitChat is a free messaging app that connects nearby devices over Bluetooth mesh and reaches internet users through Nostr. It is best for people who need a fallback when connectivity is unreliable. Its offline reach is useful, but persistent mesh identifiers and client-only Nostr private messages limit its privacy and compatibility.

Overview

BitChat routes messages over Bluetooth when it can, switches to Nostr when Bluetooth is unavailable, and queues messages when neither transport is reachable. That makes it a practical option for intermittent connectivity, including outages and areas with limited service. Queuing preserves a message for later delivery; it cannot create a connection while both transports are down.

The app requires no account, phone number, or central server. That removes common sign-up requirements, but it does not make mesh users unidentifiable: each device uses a persistent identifier derived from its identity key.

Key features

Bluetooth mesh

Nearby devices can relay messages over Bluetooth LE without internet, up to seven hops. This can extend communication beyond direct range when other BitChat devices are available, but the hop limit and dependence on nearby participants make it a contingency channel rather than broad-coverage messaging.

Nostr and location channels

Geographic chat rooms use geohash coordinates over Nostr relays, giving BitChat an internet messaging route alongside its offline mesh. Private messages use BitChat’s app-specific encrypted envelope, so they interoperate only with BitChat clients. Readers who need private messages to work across Nostr apps should choose another option.

Encryption and privacy

The whitepaper describes Noise XX for mutual authentication and forward secrecy in live mesh sessions. It also says mesh announcements expose static keys and nicknames in cleartext. A nearby passive listener can use those announcements to follow a device across time and places, a material weakness for people whose safety depends on not being tracked.

The project says the app has no analytics, advertising, telemetry, or tracking and does not sell user data. On Android, built-in Tor supports private internet connectivity. A triple-tap emergency wipe clears app data, including identity keys and queued messages, which is useful when a device needs to be cleared quickly but also removes messages waiting for delivery.

Additional tools

IRC-style commands add a familiar way to interact for users accustomed to that convention. Android also supports Wi-Fi Aware transport on compatible devices, extending its transport choices beyond Bluetooth and Nostr.

Pricing

BitChat is free. The Free plan costs nothing and is a free download for iPhone. There are no paid tiers to weigh against the offline mesh features.

Platforms

BitChat is available for Android, iOS, and macOS. The maker links to the App Store and Google Play, and Android APK releases are available through GitHub. The iOS/macOS and Android projects describe the software as released into the public domain. The project recommends installing from the App Store or building verified source, with builds checked against a per-release hash manifest.

Who it's for

BitChat suits people who want nearby messaging to continue without internet, especially in outages, disasters, protests, or areas with limited connectivity. Its automatic fallback and message queue are useful when service comes and goes. It is a weaker fit for people who need broad reach without nearby participating devices, who need private-message compatibility beyond BitChat, or who cannot accept persistent identifiers and cleartext mesh announcements.

Pros and cons

• Pro: Bluetooth mesh works without internet and relays messages up to seven hops, offering a route when conventional connectivity is unavailable.
• Pro: Automatic transport selection and queuing handle changes in connectivity without requiring users to choose a route for every message.
• Pro: No account or phone number is required, and Android adds Wi-Fi Aware support on compatible devices and built-in Tor.
• Con: Cleartext mesh announcements expose static keys and nicknames, enabling nearby observers to track a device over time and place.
• Con: Nostr private messages use a BitChat-only format, limiting compatibility with other Nostr clients.
• Con: Mesh delivery depends on nearby BitChat devices, and its seven-hop ceiling limits how far relaying can extend.

Alternatives

For encrypted messaging options with different platform coverage or plans, see Encrypted Messaging Apps.

• Olvid is a freemium alternative with Android, iOS, Linux, macOS, web, and Windows support; its free plan includes unlimited messages, unlimited attachments, secure group discussions, and ephemeral messages.
• Session is a free option for readers who want open-source code that can be independently audited; it supports Android, iOS, Linux, macOS, and Windows.
• Wire is a freemium alternative for readers who want open-source code available on GitHub, with Android, iOS, Linux, macOS, web, and Windows support.
• Berty is a free Android and iOS messenger from a non-profit organization.
• Briar is a free option for readers who need Linux, macOS, or Windows support alongside Android.
• Cwtch is another free messenger available on Android, Linux, macOS, and Windows.
• Delta Chat is a free, open-source option with Android, iOS, Linux, macOS, self-hosted, and Windows support.
• FluffyChat is free on Android, iOS, Linux, and web, with no ads.

Verdict

Choose BitChat if you need a free way to message nearby people when internet service is unreliable, and its mesh relay approach fits your situation. Its automatic routing and message queue make it a useful fallback, but cleartext mesh identifiers are a serious privacy trade-off, while BitChat-only Nostr private messages restrict compatibility. Look elsewhere if either issue is a deal-breaker.