Discord runs voice channels, text chat and communities on someone else's servers, for free, by selling your attention and a Nitro subscription. Running your own voice and text server instead means picking between how close to Discord's shape you want to stay and how much you want everything end to end encrypted.
What Discord actually does
Discord's core shape is servers made of channels: text channels for chat, voice channels you join to talk, threads, roles and permissions, and apps/bots. A self-hosted replacement for a gaming clan or a community server needs most of that shape; a replacement for a work chat usually does not need voice channels you can silently join and leave.
The open-source options at a glance
| App | Closest to | License | Stars |
|---|---|---|---|
| Fluxer | Discord's own shape: servers, channels, voice | AGPL-3.0 | about 10,600 |
| Stoat | Discord's shape, web-first today | AGPL-3.0 / MIT | about 2,700 |
| Rocket.Chat | A team's chat with voice and video | MIT (core), separate license for ee/ | about 46,200 |
| Element + a Matrix homeserver | Encrypted, federated chat and calls | Apache-2.0 | about 13,600 |
| Mumble | Voice only, nothing else | BSD-3-Clause | about 8,300 |
Fluxer
Fluxer is the one built to feel like Discord: servers, channels, voice and video calls, for friends, groups and communities, under the AGPL-3.0 license end to end. It ships as a Docker image, so standing up an instance does not need more than a server and a domain. For a gaming clan or a community moving off Discord's own servers, this is the app whose shape needs the least relearning.
Stoat
Stoat covers the same ground as Fluxer: a backend, a web client, file storage and Livekit-based video calls, deployed with Docker Compose, under AGPL-3.0 and MIT. It needs its own ports open for video (7881/tcp and a UDP range) next to the usual 80/443. Its own self-hosting docs are upfront about a real limit today: the official desktop and mobile clients do not yet support self-hosted instances, so a self-hosted Stoat server is used through its web client or the installed PWA, not the native app.
Rocket.Chat
Rocket.Chat is built for a team more than a gaming community: channels, threads, direct messages, voice and video calls, and a long list of integrations. The code is MIT-licensed outside the ee/ directories, which carry Rocket.Chat's own Enterprise license for admin and compliance features aimed at larger organizations. The free MIT core already has what a team needs to leave Discord for something it fully controls.
Element and a Matrix homeserver
Element is a client for Matrix, the open, federated chat protocol; it needs a homeserver (usually Synapse) to actually run, so this is two projects working together rather than one app. In exchange, every message, voice and video call is end-to-end encrypted by default, and a Matrix server can federate with other Matrix servers the way email servers talk to each other. Both parts are Apache-2.0. It is more setup than Fluxer or Rocket.Chat, and worth it specifically for the encryption and federation.
Mumble
Mumble does one thing: low-latency, high-quality voice chat, under the BSD-3-Clause license. There are no text channels, no servers full of bots, no file sharing. For a group that only ever wanted Discord for voice while gaming, and talks everywhere else already, a Mumble server is the lightest and cheapest thing on this list to run.
Which to pick
A community or clan replacing Discord's own shape: Fluxer first, Stoat if its web-only client today is not a problem. A work or project team: Rocket.Chat. A group that wants encryption and does not mind running two pieces: Element plus a Matrix homeserver. A group that only wants voice: Mumble.
FAQ
Is Discord open source?
No. Discord is closed-source and runs entirely on Discord's own servers; nothing about it can be self-hosted.
Can I import my Discord server into one of these?
No. None of these apps import a Discord server's channels, roles or message history; everyone has to join the new server and the structure is rebuilt by hand.
Do these alternatives have mobile apps?
Fluxer, Rocket.Chat and Element ship official mobile apps. Stoat's self-hosted instances work through its web client and PWA rather than its native apps today. Mumble has mobile clients for voice only.
Which one is the lightest to run?
Mumble, because it only handles voice: no database-heavy chat history, no file storage, no web client to serve.