Best Free Slack Alternatives for Small Teams in 2025

Slack is great software but at $7.25 per user per month, a team of 10 pays $870 per year just for messaging. For small teams and startups, that is hard to justify when free options exist.

Discord (Free)

Discord is the most popular free Slack alternative. Unlike Slack's free plan which deletes messages after 90 days, Discord keeps all message history forever for free. It also includes voice channels and video calls at no cost.

Setting up channels, threads, and roles in Discord works exactly like Slack. Most developer and startup teams have already switched.

Mattermost (Free, self-hosted)

Mattermost is an open source team messaging platform you can self-host for free. It looks and works like Slack, supports unlimited message history, and gives you complete control over your data.

Self-hosting requires a server but can be set up on a $5 per month VPS in about an hour.

Google Chat (Free)

If your team already uses Google Workspace, Google Chat is built in and free. It supports channels (called Spaces), direct messages, threads, and integrates directly with Google Drive and Meet.

Which should you pick?

- Small startup or dev team → Discord - Need full data control → Mattermost - Already on Google Workspace → Google Chat

The bottom line

Slack's core value is team messaging. All three alternatives above deliver team messaging for free. The only thing you lose is Slack's polish and some third-party integrations — neither of which justify $870 per year for most small teams.