Fluxer

Fluxer is a free and open source instant messaging and VoIP chat app for friends, groups, and communities. It offers messaging for private conversations, group chats, and channel-based communities, along with file sharing and link previews. The service is built in Sweden and is currently in public beta.

Its chat features include full Markdown support, private DMs, organized community channels, and the ability to search message history. Users can filter searches by users, dates, and other criteria, and a quick switcher with keyboard shortcuts helps move between communities and channels. Fluxer also includes moderation tools with granular roles and permissions, moderation actions, and audit logs, plus webhooks and bot support. Friend management and blocking are built in as well.

Voice and video calling are part of the app, with support for joining a call from multiple devices at once, built-in screen sharing, noise suppression, echo cancellation, and controls for muting, deafening, and camera use. Customization options include custom emojis and stickers, saving images, videos, GIFs, and audio for later, custom CSS themes, and compact mode or other display settings. The app is available for macOS, with macOS 10.15+ listed, and can also be opened in a browser. Fluxer also supports self-hosting: the backend can run on the user’s own hardware, and the project is fully open source under the AGPLv3 license. It is available in over thirty languages, and its voice and video calls connect through one of sixteen voice regions across six continents.