Discord vs Slack

Self-host either: open-source alternatives compared. · Category: team chat & community

Both Discord and Slack are in the team chat & community category. Mattermost self-hosts as a replacement for both — listed below alongside the picks unique to each.

	Discord	Slack
Category	Community / voice chat	Team chat
SaaS pricing anchor	Free; Nitro at $9.99/user/mo for power-user perks	$8.75/user/mo on Pro; message history capped on free tier
Self-host options listed	3	3

Replaces both — 1 shared open-source pick

These open-source projects appear on both /discord/ and /slack/ — picking one solves the migration off either SaaS.

Mattermost mattermost/mattermostalivereplaces both

GitHub: ★ 36.7k · last commit today
License: AGPL-3.0 (Team Edition)
Setup time: 15min docker-compose
Monthly cost: $5 VPS for ~50 daily-active users.

Picks unique to each

Discord only

Revoltalive
AGPL-3.020min docker-compose$10 VPS for a small server — Mongo + several Rust services.
Matrix (Synapse)alive
AGPL-3.030-60min (Synapse + Element web client + reverse proxy)$10 VPS for a small homeserver.

Slack only

Rocket.Chatalive
MIT15min docker-compose (Mongo + Rocket.Chat)$10 VPS — Mongo is the heavier process; tight on $5.
Zulipalive
Apache-2.030-60min (their installer script on Ubuntu 22.04)$10 VPS minimum (their installer wants 2GB+ RAM).

In a terminal? npx os-alt discord or npx os-alt slack prints either side — how the CLI works →

FAQ

Which open-source self-host alternatives replace both Discord and Slack?

1 open-source project appears on both /discord/ and /slack/: Mattermost.

How many self-host alternatives are listed for Discord and Slack?

3 for Discord, 3 for Slack.

Are all the self-host alternatives free?

Yes — every listed option is open source. Your cost is the VPS or hardware that runs it.