What is ZapFast used for?

ZapFast is a native WhatsApp desktop client for Linux, macOS and Windows written in Rust with egui, which links to your phone as a companion device. It is a good fit for using WhatsApp on desktop without a browser tab, lower memory messaging on older computers and searching message history by date.

Is ZapFast open source?

Yes. ZapFast is open source under the MIT licence. Its source code is on GitHub at crmne/zapfast and is written mainly in Rust.

Yes. ZapFast is open source, so the software itself is free to use.

Can I self-host ZapFast?

Yes. ZapFast can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is ZapFast an alternative to?

ZapFast is an open-source alternative to WhatsApp. Other open-source alternatives to WhatsApp include Telegram Desktop, Tuwunel and Telegram for Android.

Is ZapFast actively maintained?

Yes. The most recent commit to ZapFast was on 2 October 2026, and the latest release is v0.18.2, published on 30 September 2026. The project has 1.2k stars on GitHub.

ZapFast: open-source alternative to WhatsApp

About ZapFast

ZapFast is a WhatsApp client built in Rust with the egui interface toolkit, aimed at being fast and light compared with browser-based clients. It uses the whatsapp-rust library to speak the WhatsApp Web protocol, runs without a browser engine, and links to your phone as a companion device by QR code or phone number.

After linking, recent history is copied to the computer and stored locally. The client shows pinned, unread, muted and archived chats, typing indicators and message status, and offers search across chats, saved messages and contacts, including an in-chat search pane with date filtering. Groups and followed channels can be left from a context menu with an option to archive them. The README says startup takes under a second in its Linux test and gives memory measurements.

ZapFast is licensed under MIT and runs on Linux, macOS and Windows, with downloads and guides on its website. It is a third-party client for a proprietary messaging service, so it relies on the WhatsApp Web protocol and may be affected by changes there. A sibling project offers a similarly native Spotify client. It suits desktop users who prefer a lightweight native app.

Key features

Native Rust and egui interface
Link to phone by QR code or number
Chat list with pinned, unread, and archived views
Search across chats and messages
Local storage of recent history
Linux, macOS, and Windows builds

Good fit for

→Using WhatsApp on desktop without a browser tab
→Lower memory messaging on older computers
→Searching message history by date

Built with: Rust
Tags: whatsapp; messaging; desktop-app; rust; egui; native; chat-client; cross-platform; linux

ZapFast: questions and answers

What is ZapFast used for?: ZapFast is a native WhatsApp desktop client for Linux, macOS and Windows written in Rust with egui, which links to your phone as a companion device. It is a good fit for using WhatsApp on desktop without a browser tab, lower memory messaging on older computers and searching message history by date.
Is ZapFast open source?: Yes. ZapFast is open source under the MIT licence. Its source code is on GitHub at crmne/zapfast and is written mainly in Rust.
Is ZapFast free?: Yes. ZapFast is open source, so the software itself is free to use.
Can I self-host ZapFast?: Yes. ZapFast can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is ZapFast an alternative to?: ZapFast is an open-source alternative to WhatsApp. Other open-source alternatives to WhatsApp include Telegram Desktop, Tuwunel and Telegram for Android.
Is ZapFast actively maintained?: Yes. The most recent commit to ZapFast was on 2 October 2026, and the latest release is v0.18.2, published on 30 September 2026. The project has 1.2k stars on GitHub.