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Last checked October 15, 2026

Best Free Alternatives to Slack (2026)

Slack is the default work chat tool: channels, threads, huddles, and a large app directory. The Pro plan is what most teams buy once the free history window is too short.

Small teamsStartupsEnterprisesPrice checked

What Slack costs

Pro is $7.25 per active user/month billed annually, or $8.75 billed monthly.

Slack also sells Business+ and Enterprise Grid above Pro. The free plan exists; this check did not re-quote its history limit from Slack's own page, so it is not stated as a fact here.

Slack website·Pricing source

Ranked by Drop-in score

How we rank

#1 is the highest-scoring alternative that is not sponsored. A featured listing, when one is sold, is labeled and sits after #1.

  1. 96
    #1Open source

    Mattermost

    Self-hosted team chat that follows the Slack model.

    Last checked October 15, 2026 · MIT for Team Edition binaries; see Mattermost's license FAQ for source terms

    MacWindowsLinuxiOSAndroidWebSelf-host
    Cost and detailsMigration guideWebsite
  2. 91
    #2Open source

    Rocket.Chat

    MIT-licensed team chat with a free community server.

    Last checked October 15, 2026 · MIT (Community)

    MacWindowsLinuxiOSAndroidWebSelf-host
    Cost and detailsWebsite
  3. 90
    #3Open source

    Zulip

    Open-source chat organized by topics instead of threads.

    Last checked October 15, 2026 · Apache-2.0

    MacWindowsLinuxiOSAndroidWebSelf-host
    Cost and detailsWebsite
  4. 76
    #4Open source

    Element

    A Matrix client for encrypted, federated chat.

    Last checked October 15, 2026 · Apache-2.0

    MacWindowsLinuxiOSAndroidWebSelf-host
    Cost and detailsWebsite

Feature by feature

Full is the whole job. Partial is a real version with a gap. Missing means it does not do this. Not checked counts as zero in the score.

FeatureMattermost#1 · 96Rocket.Chat#2 · 91Zulip#3 · 90Element#4 · 76
ChannelsWeight 10FullFullFullFull
Threaded conversationsWeight 8FullFullPartialTopics replace Slack threads. The history is easier to scan and the habits are different.PartialMatrix threads exist. Clients differ in how completely they show them.
Direct messagesWeight 8FullFullFullFull
Full message searchWeight 8FullFullFullPartialSearch depends on the homeserver and is weaker than Slack.
File sharingWeight 5FullFullFullFull
Integrations and botsWeight 7FullPartialThe community app catalog is smaller than Slack's, and some apps are premium.FullPartialBots and bridges exist, including a Slack bridge. There is no Slack-sized app directory.
Voice and video callsWeight 6PartialCalls exist. They are not a Zoom replacement and depend on configuration.PartialBuilt-in calls exist. Quality and scale depend on the deployment.PartialVoice and video are delegated to Jitsi, Zoom, or BigBlueButton.PartialElement Call covers voice and video. It is younger than Slack huddles.
Self-hostingWeight 8FullFullFullFull
Mobile appsWeight 5FullFullFullFull
Guest accountsWeight 4FullFullFullPartialGuest access exists in Matrix and is less of a productized toggle than Slack's.

Real cost

Mattermost

Free tier
Team Edition is free to self-host. Mattermost also sells cloud and Enterprise subscriptions.
Hosted plan
No hosted price recorded.
Self-hosting
Moderate. A single-server Docker or tarball install is documented. Preview and push notifications need extra setup. Approximate server cost: $10–25/mo for a small team server. Unverified estimate.

Rocket.Chat

Free tier
Community is free to self-host. A hosted Starter plan for up to 50 users is also free.
Hosted plan
No hosted price recorded.
Self-hosting
Moderate. Docker Compose is documented. Snapshots, push, and federation add moving parts. Approximate server cost: $10–25/mo for a small server. Unverified estimate.

Zulip

Free tier
Cloud Free includes 10,000 messages of search history and 5 GB of file storage. Many open-source, research, and non-profit groups qualify for a free Standard plan.
Hosted plan
Cloud Standard is $6.67 per user/month billed annually, or $8 billed monthly. Plus requires a 10-user minimum. Self-hosting the software is free; paid self-hosted plans are support tiers.
Self-hosting
Moderate. The installer supports Docker and traditional Linux. A small organization fits on one VM. Mobile push for more than 10 users needs Zulip's push service or a sponsorship plan. Approximate server cost: $10–20/mo for a small server. Unverified estimate.

Element

Free tier
You can use the public matrix.org homeserver or host your own. Element also sells hosted and enterprise Matrix.
Hosted plan
No hosted price recorded.
Self-hosting
Hard. A Synapse or Dendrite homeserver plus Element Web is a real ops project. Federation and push are the parts that take time.

Top pair

Migrate from Slack to Mattermost

Mattermost can import a Slack export. What you get is channels and message history, not huddles, canvases, or app workflows.

Read the migration guide

Questions