Open-Source Slack & Microsoft Teams Alternatives

Compare privacy-first team chat alternatives to Slack and Microsoft Teams, including Zulip and Element (Matrix), with real pricing and catches.

Zulip

Replaces Slack, Microsoft Teams

US · United States

Free (10k msg history) · Self-host free · Cloud from $6.67/user/mo

Open-source team chat organized by topic threads so async conversations never get buried in noisy channels.

Open Source Self-Hostable Free Tier Zero-Tracking / E2EE

The Catch: Topic-based threading takes a few days to learn if your team is used to Slack-style flat channels.

Replaces Slack, Discord, Microsoft Teams

UK · United Kingdom

Free (public/self-hosted) · Cloud from $5/user/mo

Decentralized, end-to-end encrypted team and community chat built on the open Matrix protocol.

Open Source Self-Hostable Free Tier Outside US Zero-Tracking / E2EE

The Catch: Encrypted key backup/verification can confuse non-technical users, and self-hosting Synapse needs careful tuning.

Tool	HQ	Pricing	Open Source	Self-Hostable
Zulip	United States	Free (10k msg history) · Self-host free · Cloud from $6.67/user/mo	Yes	Yes
Element (Matrix)	United Kingdom	Free (public/self-hosted) · Cloud from $5/user/mo	Yes	Yes

Zulip organizes every channel by topic threads so conversations stay structured without constant real-time noise.

Yes—Element (built on Matrix) is open source, federated, and supports E2EE on your own server.