Chat & meetings

Alternatives to Slack

Compare these candidates if you want self-hosting, data control or less dependence on Slack's hosted service. Actual costs depend on deployment and required features.

Compare chat, community voice and meetings separately; check push notifications, federation and operations.

Compare candidates

Growth uses the latest collected snapshots; — means unavailable. Stars and licenses are not substitutes for feature verification.
Project	Stars	7-day gain	Language	License	Maintenance
mattermost	39,499	—	TypeScript	Review requiredReview license scope and restrictions	✅ Recently maintained
zulip	26,154	—	Python	Apache-2.0	✅ Recently maintained

mattermost

mattermost/mattermost

Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..

✅ Recently maintained

Match the project description to required features, then trial migration and deployment with a small real dataset.

Repository verified 2026-11-02 · Official repository & installation

zulip

zulip/zulip

Zulip server and web application. Open-source team chat that helps teams stay productive and focused.

✅ Recently maintained

Match the project description to required features, then trial migration and deployment with a small real dataset.

Repository verified 2026-11-02 · Official repository & installation

Before migrating

Check exports/imports, required features, permissions, backups, security updates and total operating cost. Candidates are not guaranteed feature-equivalent; enterprise extensions and model services may have separate terms and costs.