Alternatives to Slack

4 self-hosted alternatives — 3 medium, 1 hard

Why people look for alternatives

  • Expensive per-user pricing for small and medium teams
  • Message history limited on free plan
  • Data stored on Slack servers with no self-hosting option
  • Frequent UI changes and feature bloat
AppDifficultyMin RAMDockerMobileActive
Element

Decentralized encrypted messaging client built on the Matrix protocol.

hard2 GB iOS & AndroidYes
Mattermost

Secure team messaging platform designed as a Slack alternative for organizations.

medium2 GB iOS & AndroidYes
Rocket.Chat

Team communication platform with channels, direct messaging, and video calls.

medium2 GB iOS & AndroidYes
Zulip

Threaded team chat that combines real-time messaging with email-like topic threading.

medium2 GB iOS & AndroidYes
Element

Decentralized encrypted messaging client built on the Matrix protocol.

Pros

  • + End-to-end encryption by default
  • + Federated - no single point of control
  • + Bridges to other platforms like Slack and Discord
  • + Active development by Element HQ

Cons

  • - Complex server setup with Synapse
  • - Federation can be slow
  • - Resource hungry for small deployments
  • - UI can feel cluttered
Mattermost

Secure team messaging platform designed as a Slack alternative for organizations.

Pros

  • + Clean Slack-like interface
  • + Good DevOps integrations
  • + Strong security and compliance features
  • + Excellent mobile apps

Cons

  • - Many features require Enterprise license
  • - Plugin ecosystem smaller than Slack
  • - Can feel bloated for small teams
  • - Frequent breaking changes in plugins
Rocket.Chat

Team communication platform with channels, direct messaging, and video calls.

Pros

  • + Rich feature set out of the box
  • + Good mobile apps
  • + Extensive integration options
  • + Active community

Cons

  • - Can be resource heavy
  • - Free tier limitations increasing
  • - MongoDB dependency
  • - Some features moved to paid tiers
Zulip

Threaded team chat that combines real-time messaging with email-like topic threading.

Pros

  • + Unique topic-based threading model
  • + Great for async communication
  • + Fully open source with no paid tiers for self-hosted
  • + Excellent search

Cons

  • - Threading model has a learning curve
  • - Fewer integrations than Slack
  • - Smaller community
  • - UI feels dated compared to alternatives