head to head
Slack vs Zulip
Zulip is the open source alternative to Slack — channel-based team messaging platform. Here is the honest comparison.
Yes — Zulip is a viable free replacement for Slack. Zulip is open source under Apache-2.0, written in Python, with 25,921 GitHub stars, 10,247 forks and 2,008 open issues; it was last pushed 14 hours ago. Slack costs from $8, while self-hosting Zulip carries no licence fee — the trade is your operational time instead of a subscription. 3 other open source Slack alternatives are tracked here, led by Mattermost at 39,093 stars. Zulip ranks #3 of 4 tracked open source Slack alternatives by stars. The tracked set, by adoption: Mattermost (39,093 stars), Jitsi (29,931 stars), Element (13,461 stars). Replacement criteria on this page: 4 reasons to move to Zulip and 3 reasons to stay on Slack.
choose Zulip if
- Your Slack bill is growing with seats or usage
- You need your data in a format and server you control
- Your compliance posture requires auditing the code that touches sensitive data
- You have (or can rent) a server and basic Docker comfort
stick with Slack if
- You need the polished onboarding and support SLAs of a commercial vendor
- Your team has zero capacity to operate software, even self-hosted-simple
- You depend on a Slack integration ecosystem that the OSS alternatives have not replicated
Side by side
| Zulip (open source) | Slack | |
|---|---|---|
| Price | Free (self-hosted) | $8.75-$12.50/user/month |
| License | Apache-2.0 | Proprietary |
| Source code | Public, auditable | Closed |
| Self-hosting | Yes — zulip/zulip | Cloud only |
| Data ownership | Your server, your format | Vendor's cloud |
| Community | ★ 26K · ⑂ 10K | — |
| Built with | Python | — |
Why people look for a Slack alternative
About Zulip
Zulip is an open source organized team chat application built on topic based threading, aimed at distributed teams that need live and asynchronous conversation in one place, and it is positioned as an open alternative to Slack.
read the full Zulip overview →
Other open source alternatives to Slack
last updated nightly · ranking method: github stars, live-tracked
Frequently asked questions
Is Zulip a good replacement for Slack?
Zulip is an open source alternative to Slack (Channel-based team messaging platform). It is written in Python and licensed under Apache-2.0, with 25,921 GitHub stars.
Is Zulip free compared to Slack?
Yes. Zulip is open source — there is no licence fee, and you can self-host it. Slack is typically a paid subscription, so the trade-off is licence cost against the operational work of running it yourself.
How do I migrate from Slack to Zulip?
Migration effort depends on the data formats involved. Check Zulip's documentation for import options, and compare the feature table above to confirm the capabilities you depend on are covered before switching.