# Private and open-source alternatives to Slack

1. [Campfire](https://privacyratings.com/team-chat/campfire/): B (80/100). Self-hosted group chat web app from 37signals with rooms, direct messages, file attachments, search and bot integrations, distributed through ONCE.
2. [Xeres](https://privacyratings.com/team-chat/xeres/): B (80/100). A decentralized, encrypted P2P friend-to-friend app for chat, forums, channels, boards, voice calls and anonymous file sharing.
3. [Nextcloud Talk](https://privacyratings.com/team-chat/nextcloud-talk/): C (65/100). Chat, audio and video call app for Nextcloud servers, with group conversations, screen sharing, desktop and mobile clients, and optional federation between servers.
4. [Stoat](https://privacyratings.com/team-chat/stoat/): C (65/100). Open source chat platform for friends and communities with servers, channels, direct messages and voice chat, formerly named Revolt. The server software can be self-hosted.
5. [Zulip](https://privacyratings.com/team-chat/zulip/): C (65/100). Open source team chat that organizes conversations into channels and named topics. It can be self-hosted or used as the Zulip Cloud service run by Kandra Labs.
6. [Element](https://privacyratings.com/team-chat/element/): C (60/100). Matrix client for web, desktop and mobile with end-to-end encrypted chats, group rooms, file sharing and voice and video calls. Built by Element, which also sells hosted and self-hosted Matrix servers.
7. [Rocket.Chat](https://privacyratings.com/team-chat/rocket-chat/): D (50/100). Self-hostable team chat platform with web, desktop and mobile apps, federation and many integrations. End-to-end encryption is available but off by default, so workspace admins can otherwise read messages.
8. [Mattermost](https://privacyratings.com/team-chat/mattermost/): D (45/100). Self-hostable team chat with channels, threads, calls and integrations, with desktop, mobile and web apps. Messages are not end-to-end encrypted, and server telemetry is on by default but can be turned off.

Source: https://privacyratings.com/alternatives/slack/