Slack Alternatives

Discussions recommend open-source and self-hosted alternatives to Slack, such as Mattermost, Rocket.Chat, Zulip, and Matrix, for team communication, often highlighting self-hosting options and comparisons to proprietary tools.

📉 Falling 0.4x Open Source
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Keywords

e.g flock.com XMPP zulip.com Rocket.Chat youtube.com OCS UI mattermost.com antbuddy.com slack self host host rocket discord chat self skype teams open source

Sample Comments

notwhereyouare Feb 20, 2018 View on HN

have you considered rocket chat? It's a slack you can either have hosted for you, or host in house.

johnchristopher Feb 10, 2017 View on HN

Have you considered mattermost ?

aembleton Jul 26, 2024 View on HN

Have you tried Mattermost? I've never used it but it looks like it might work for you.https://mattermost.com/

umvi Mar 14, 2019 View on HN

There are alternatives, like Zuliphttps://zulipchat.com/

ywecur Nov 1, 2015 View on HN

So use Rocket.chat or Mattermost

jkepler Dec 21, 2018 View on HN

Mattermost, anyone? Its a libre Slack replacement, with additional functionalities.

smt88 Feb 1, 2016 View on HN

Why not Mattermost?http://www.mattermost.org/

a1o Jun 25, 2024 View on HN

Rocket Chat is a possible alternative. Also Teams and Discord.

v3ss0n Sep 18, 2025 View on HN

Zulip is much better alternative due it it's threaded nature and it have nice slack import tool. Please give a try.

malermeister Apr 1, 2023 View on HN

I think Mattermost might fit the bill?