What it does
Fluid Chat is an open-source team chat with public/private channels, direct messages, threads, reactions, files, search, presence, reminders, scheduled sends, and webhooks. Its site offers hosted and self-hosted options.
Fluid Chat supplies a channel-based messaging workflow with threads, group DMs, search, file sharing, scheduled sends, webhooks, retention settings, and audit records. The vendor says hosted and self-hosted use are free, with no per-seat charge. Its site documents hosted limits: 10 MiB per upload, 100 MiB active files per workspace, and 15-day upload expiry; it also says native mobile apps and Slack import are not available yet. No account or deployment was tested.
Strengths
- Free and open source, with hosted or self-hosted use, according to the vendor.
- Includes threads, search, retention settings, export, and an audit log.
- No hosted per-seat fee is listed.
Watch out for
- Hosted storage and upload limits are documented, including 15-day upload expiry.
- The vendor says native mobile apps and Slack import are not available.
Best for
- Teams seeking channel-based open-source chat without per-seat billing
- Technical teams wanting to self-host and configure retention
Sources
- Fluid Chat — the free, open source Slack alternative (Oct 25, 2026)