ZapFast is an independent, open-source desktop application that brings WhatsApp to Linux, macOS, and Windows through a lightweight native interface. Designed for speed and everyday communication, it opens in under a second and uses about 200 MB of RAM, without relying on a browser engine. Users can chat, play, seek, and record voice messages, with built-in OGG/Opus support. The app displays photos, GIFs, stickers, documents, polls, locations, and link previews, and lets users add captions before sharing files.

ZapFast can remain linked in the system tray when its window is closed, while notifications show the chat picture and muted conversations remain quiet. Keyboard shortcuts support searching, switching chats, replying, and recording; users can also select and copy text across messages. Built with Rust and egui, ZapFast is MIT-licensed, and its linking process is documented. It is made by Carmine Paolino and shares a foundation with sibling app Spotifast. ZapFast is not affiliated with or endorsed by WhatsApp LLC or Meta.