10 open-source alternatives · Updated daily
Slack charges $7–$15 per user per month.

Open-source alternatives to Slack

10 self-hostable open-source projects that replace Slack, ranked by computed health score with real self-hosting cost. Save up to $34/yr per seat by self-hosting on a $4.13/mo VPS.

Cheapest path: zulip on hetzner for $4.13/mo, that's about $34/year less than Slack.

10
OSS alternatives
$4.13
Cheapest /mo
$7+
Slack /mo
$34
Yearly savings

Why people leave Slack

  • Free tier hides messages older than 90 days
  • Per-seat pricing ($7-15/user/mo) gets expensive past 20 people
  • No self-hosting option even on Enterprise Grid
  • Storage is capped per workspace

Mattermost, Rocket.Chat, and Zulip give the same channels, threads, and integrations on your infra with full message history forever.

The 10 alternatives, ranked by health

Health score is a 6-dimension composite. See methodology for formula and weights.

zulip
by zulip
81/100

Zulip server and web application. Open-source team chat that helps teams stay productive and focused.

Python Apache-2.0
25k
$4.13/mo
2/5
Rocket.Chat
by RocketChat
81/100

The Secure CommsOS™ for mission-critical operations

TypeScript NOASSERTION
45k
$4.13/mo
2/5
slack
by slack-go
77/100

Slack API in Go

Go BSD-2-Clause
4.9k
$4.13/mo
2/5
gatus
by TwinProduction
74/100

Automated developer-oriented status page with alerting and incident support

Go Apache-2.0
11k
$4.13/mo
2/5
Zewo
by Zewo
72/100

Lightweight library for web server applications in Swift on macOS and Linux powered by coroutines.

Swift MIT
1.8k
$4.13/mo
2/5
Peek
by shaps80
61/100

All new design. Inspect your iOS application at runtime.

Swift MIT
2.6k
$4.13/mo
2/5
colanode
by colanode
56/100

Open-source and local-first Slack and Notion alternative that puts you in control of your data

TypeScript Apache-2.0
4.8k
$4.13/mo
2/5
statusok
by sanathp
49/100

Monitor your Website and APIs from your Computer. Get Notified through Slack, E-mail when your server is down or response time is more than expected.

Go NOASSERTION
1.6k
$4.13/mo
2/5
talkyard
by debiki
46/100

A community discussion platform: Brings together the main features from StackOverflow, Slack, Discourse, Reddit, and Disqus blog comments.

TypeScript AGPL-3.0
1.8k
$4.13/mo
2/5
metabase
by metabase
44/100

The easy-to-use open source Business Intelligence and Embedded Analytics tool that lets everyone work with data

Clojure NOASSERTION
47k
$4.13/mo
3/5

Cost comparison vs Slack

Self-hosting cost on cheapest plan meeting requirements vs Slack entry tier ($7/mo).

ProjectSelf-host /moSlack /moSave /yr
zulip $4.13 $7+ $34 Deploy →
Rocket.Chat $4.13 $7+ $34 Deploy →
slack $4.13 $7+ $34 Deploy →
gatus $4.13 $7+ $34 Deploy →
Zewo $4.13 $7+ $34 Deploy →
Peek $4.13 $7+ $34 Deploy →
colanode $4.13 $7+ $34 Deploy →
statusok $4.13 $7+ $34 Deploy →

Pick your alternative

Most operators land on zulip (top health score in this category; cheapest VPS path is zulip on hetzner for $4.13/mo).

Data refreshed daily. Pricing for Slack sourced from official site.

Last verified . Data refreshes every 30 minutes.