Slack vs Mattermost
Last updated July 6, 2026
Deciding between Slack and Mattermost? Here's how they stack up on price, fit and migration effort — so you can pick the right team communication tool without second-guessing.
Pricing disclaimer: All prices are list prices in USD, shown for general information only as of July 6, 2026, and may have changed since. Plans, tiers and features vary by region and are frequently updated by each vendor. Nothing here is financial, legal or purchasing advice — always confirm current pricing and terms on the provider's official website before you buy.
| Slack | Mattermost | |
|---|---|---|
| Starting price | Free (Pro $8.75/user/mo) | Free |
| Free tier | — | Yes |
| Best for | Established users on its plans | Security- and compliance-driven orgs that must self-host their chat. |
| Migration effort | — | Hard |
| Rating | — | 4.2 ★ |
Why teams switch from Slack
- ✕The free plan now hides messages older than 90 days, pushing teams to pay to keep history.
- ✕Per-seat pricing ($8.75–$18/user/mo) gets expensive for larger teams.
- ✕No self-hosting or data ownership — everything lives on Slack's cloud.
- ✕Price increases and feature gating into higher tiers.
Where Mattermost wins
- ✓Complete data ownership & control
- ✓Strong security/compliance posture
- ✓Familiar Slack-like interface
…and where it doesn't
- ✕Requires self-hosting/infrastructure
- ✕Public pricing not transparent
- ✕IT overhead to run
The verdict on Mattermost
Mattermost is the choice for organizations whose reason for leaving Slack is data sovereignty — government, defense, finance and security-conscious engineering teams that must self-host communications. It's open source with a familiar Slack-like interface, gives you complete control over your data and compliance, and integrates well with DevOps and security tooling. The trade-offs are real: you run the infrastructure, its paid tiers are contact-sales rather than transparently priced, and there's meaningful IT overhead. But when self-hosting and control are non-negotiable, Mattermost is the leading answer, and it imports Slack exports directly. (Paid pricing pending verification.)
Try Mattermost freeWhat real users say: Slack vs Mattermost
Real Slack-vs-Mattermost discussions from Reddit — click any thread to read it at the source.
Thread titles and links are shown for reference and point back to Reddit. QikAlt does not reproduce comment content. Reddit is a trademark of its respective owner.
Frequently asked questions
Is Mattermost cheaper than Slack?
Mattermost starts at Free, including a free tier, compared with Slack from Free (Pro $8.75/user/mo). Free & open source (self-hosted). Paid Professional/Enterprise tiers are contact-sales — pricing pending verification (Jul 6, 2026).
Is it hard to migrate from Slack to Mattermost?
Migration difficulty is rated Hard. (Paid pricing pending verification.)
Who should choose Mattermost over Slack?
Mattermost is best for: Security- and compliance-driven orgs that must self-host their chat. If that describes your situation, it's a strong Slack alternative.
Disclosure: some links are affiliate links; QikAlt may earn a commission at no cost to you. Pricing is list price as of July 6, 2026 and may change — confirm on each vendor's site.