Top pick: Zulip. Switching saves about $87 USD a year.
$87 USDa year
≈$124.04 CAD (converted from USD)
Every pick below has a free version.
4 alternatives
The editor’s first choice for most people switching.
Best for teams that want open-source chat with threads
Free to self-host under Apache-2.0. Zulip Cloud Free keeps 10,000 messages of search history and 5 GB of files. Topic threading takes time to get used to. Free version: Self-hosting is free. Zulip Cloud Free keeps 10,000 messages of search history and 5 GB of file storage.
Covers most of the same work, with trade-offs noted on each card.
Best for a Slack-like interface you host yourself
Free to run as Entry edition or the MIT Team Edition (about 250 users, SSO being removed). Entry is meant for teams under 50 and caps history at 10,000 messages. Free version: Self-hosted Entry edition is free with 10,000 messages of history and community support. Paid plans remove the limits and add support.
Best for federated chat you can run on your own server
The Community edition is free under AGPL-3.0 when self-hosted. Element lists no public USD price for its hosted or Enterprise plans. Free version: The client and the Element Server Suite Community edition are free to use and host. Paid Pro and Sovereign plans add support and scale.
Right for specific needs, or not yet mature enough to recommend widely.
Best for self-hosted chat with omnichannel support tools
Community is MIT and self-hosted, limited to 100 concurrent users. Its docs advise against relying on it for business-critical use. Starter is free for up to 50 users. Free version: Community: up to 100 concurrent users and 10,000 push notifications a month. Starter is free for up to 50 users.
Sponsor this page: $149 for 30 days. Sponsors appear above the ranking, labeled; the ranking itself is not for sale.
How each alternative covers what people use Slack for. Numbers link to editor notes.
| Feature | Zulip | Mattermost | Element | Rocket.Chat |
|---|---|---|---|---|
| Messaging | ||||
| Channels, threads and direct messages | YesNote 1Every message belongs to a topic inside a stream, which differs from Slack's channels | Yes | YesNote 2Rooms, spaces, threads and direct messages | Yes |
| Searchable message history | YesNote 3Self-hosted servers have no message history limit | PartialNote 4Entry edition shows only the latest 10,000 channel messages across all channels | PartialNote 5Encrypted rooms are searchable only in the desktop app | Yes |
| Calls | ||||
| Voice and video calls (huddles) | PartialNote 6The call button starts a Jitsi Meet room by default; no built-in huddles | PartialNote 71:1 audio and screen share; group calls and video are limited or experimental | PartialNote 8Element Call needs a LiveKit server when you self-host it | PartialNote 9Community video calls use Jitsi or BigBlueButton only |
| Integrations | ||||
| Apps, bots and webhooks | YesNote 10Incoming and outgoing webhooks plus a bot API and many built-in integrations | YesNote 11Webhooks, slash commands, bots and plugins | PartialNote 12Matrix bots, widgets and bridges; no app directory like Slack's | PartialNote 13Community enables 5 public apps and no private apps; webhooks work |
| No-code workflow automation | NoNote 14No workflow builder; automation needs bots or webhooks | PartialNote 15Playbooks run checklists and runbooks; Entry plans a limit of 5 active runs a month | No | No |
| Collaboration | ||||
| Channels shared with other organizations | NoNote 16Guest users join your organization; channels are not shared between organizations | PartialNote 17Connected workspaces work on Entry but need Enterprise builds and config file settings | YesNote 18Matrix federation lets rooms span different servers | NoNote 19Federation is not part of the Community edition |
| Access | ||||
| Mobile apps with push notifications | PartialNote 20Self-hosted push is free for 10 users; larger servers need a paid plan or an eligible community | YesNote 21Entry plans a cap of 10,000 push notifications a month | Yes | PartialNote 22Community push notifications are capped at 10,000 a month |
| Parity score | 57% | 71% | 64% | 50% |
Not covered by any free alternative yet: Voice and video calls (huddles), No-code workflow automation. See all feature gaps
Switching saves about $87 USD / ≈$124 CAD (estimated from the USD price) a year. Prices checked ; ≈ means converted from USD.
Based on Slack Pro, per user. Price source. USD to CAD at 1.4257 as of Oct 7, 2026.
Last verified . Ranking: tier first, then the published score.
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Slack is a product of Slack Technologies, named here for comparison only. Platforms listed for Slack: Windows, macOS, Linux, Web, iOS, Android.