2 Best Open-Source Alternatives to Stoat (formerly Revolt) in 2026
By Noahlast updated
All 3 Stoat (formerly Revolt) alternatives
Compared: open-source alternatives to Stoat (formerly Revolt)
| Alternative | Best for | Standout | Biggest weakness | Learning curve | Price |
|---|---|---|---|---|---|
| Stoat (formerly Revolt)reference | communities and friend groups who want a Discord-style chat app that is open source, self-hostable, and free of a paid subscription tier | Fully open-source and self-hostable Discord alternative (AGPL-3.0) that offers custom emoji and animated avatars to every user with no subscription required. | The 2026 rebrand from Revolt to Stoat means links, bookmarks, and search results still pointing to revolt.chat or the old revoltchat GitHub org can confuse users mid-transition, and the client apps and self-hosted community are smaller than Discord's, so third-party bots and integrations are far more limited. | Low | Free |
| Rocket.Chat | regulated and security-conscious organizations (government, defense, healthcare, financial services) that need a self-hostable or air-gapped team chat platform, plus teams wanting a free, open-source Slack alternative | A fully open-source (MIT-licensed), self-hosted Community Edition with no user limit, alongside government and defense deployment options authorized up to DoD Impact Level 6 for classified environments. | None of the paid tiers publish list pricing — Commercial, Government, and Defense plans all require contacting sales for a quote, making it hard to budget or compare costs against competitors like Slack or Mattermost without a sales call. | Moderate | Free |
| Mattermost | regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls a SaaS-only tool like Slack can't provide | Deployment flexibility for compliance-sensitive organizations: the same platform can run fully air-gapped or in a sovereign cloud with FIPS 140-3/STIG-hardened compliance options, not available from mainstream SaaS chat tools. | No paid tier publishes flat per-user pricing; Professional, Enterprise, and Enterprise Advanced all require a sales conversation and prepaid annual seat commitment, making it harder to budget or compare cost against competitors up front, and self-hosting the free core requires ongoing server maintenance. | Moderate | Free |
Stoat (formerly Revolt)
Rocket.Chat
Mattermost1.Rocket.Chat — best Stoat (formerly Revolt) alternative for regulated and security-conscious organizations (government, defense, healthcare, financial services) that need a self-hostable or air-gapped team chat platform, plus teams wanting a free, open-source Slack alternative
Rocket.Chat is the best Stoat alternative for regulated and security-conscious organizations, government agencies, defense contractors, and healthcare operators, that need a self-hostable team chat platform with compliance and air-gapped deployment options. Rocket.Chat's Community Edition is free, MIT-licensed, and has no user limit, comparable to Stoat's own fully free AGPL-3.0 plan, and it has earned a track record Stoat lacks: a 4.3/5 rating from 156 Capterra reviews versus Stoat's zero external ratings on file. Rocket.Chat's GitHub project carries over 46,000 stars, a scale of open-source adoption not documented for Stoat. Where Rocket.Chat separates itself from Stoat is its Defense tier, which supports air-gapped deployment authorized up to DoD Impact Level 6 with FIPS 140-3 cryptography, a compliance depth Stoat's community-focused listing doesn't address. Stoat remains the better choice for communities and friend groups that want to avoid a sales conversation entirely: none of Rocket.Chat's Commercial, Government, or Defense tiers publish list pricing, all three require contacting sales for a quote, while Stoat's entire feature set, custom emoji and animated avatars included, stays free with zero tiers to negotiate.
Compared to Stoat: 4.3/5 rating from 156 Capterra reviews vs Stoat's none on file, Defense tier authorized up to DoD Impact Level 6 with FIPS 140-3 cryptography unlike anything in Stoat's listing, Commercial/Government/Defense tiers are quote-only with no published pricing unlike Stoat's fully free $0 plan
Wins:4.3/5 rating from 156 Capterra reviews, evidence Stoat has none of on file · Defense tier supports air-gapped deployment authorized up to DoD Impact Level 6 with FIPS 140-3 cryptography, a compliance depth not documented in Stoat's listing
Loses:None of the Commercial, Government, or Defense tiers publish list pricing, all three require contacting sales, unlike Stoat's fully free plan with zero tiers to negotiate · Moderate learning curve per its own listing, versus Stoat's low learning curve
Pros
- Community Edition is free, open-source (MIT license), and self-hostable with no user limit.
- Deployment options span standard cloud hosting to fully air-gapped, classified environments.
- Federated communications let separate Rocket.Chat deployments message across organizational boundaries.
- Extensible via custom and pre-built apps, plus native voice, video, and screen sharing.
Cons
- No published list pricing for any paid tier; every quote requires a sales conversation.
- Self-hosting the Community Edition adds administration and infrastructure overhead compared to SaaS competitors.
- Government/Defense-specific features add complexity that most mainstream business customers won't need.
Pricing: Free — Community edition free ($0), matching Stoat's plan; Commercial/Government/Defense tiers are quote-only with no published dollar figure, while Stoat has no paid tier to compare (verified undefined NaN, NaN)
2.Mattermost — best Stoat (formerly Revolt) alternative for regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls a SaaS-only tool like Slack can't provide
Mattermost is the best Stoat alternative for regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls Stoat's community-focused platform doesn't document. Mattermost's free core is MIT-licensed and self-hostable with no user limit, the same no-cost baseline as Stoat's AGPL-3.0 plan, and it's used by organizations including the U.S. Air Force, NASA, and Samsung, adoption evidence Stoat's listing has nothing comparable to. Mattermost holds a 5/5 rating on Product Hunt, though that score is built from just 1 review, still a rating Stoat's own listing has none of at all. Its Enterprise Advanced tier supports up to 200,000 concurrent users with mobile biometrics, data-at-rest encryption, and burn-on-read messages, a scale and feature depth well beyond Stoat's single free tier. Stoat remains the better choice for anyone who wants to avoid a prepaid annual seat commitment: Professional, Enterprise, and Enterprise Advanced are all sold as prepaid annual subscriptions with no published flat pricing, every quote requires a sales conversation, while Stoat's entire feature set, including custom emoji and animated avatars, stays free for every user with no subscription tier at all.
Compared to Stoat: used by the U.S. Air Force, NASA, and Samsung, adoption evidence not documented in Stoat's listing, Enterprise Advanced tier supports up to 200,000 concurrent users with mobile biometrics and data-at-rest encryption far beyond Stoat's single free tier, Professional/Enterprise/Enterprise Advanced require a prepaid annual sales conversation with no published pricing unlike Stoat's fully free $0 plan
Wins:Used by organizations including the U.S. Air Force, NASA, and Samsung, adoption evidence not documented in Stoat's listing · Enterprise Advanced tier supports up to 200,000 concurrent users with mobile biometrics, data-at-rest encryption, and burn-on-read messages, well beyond Stoat's single free tier
Loses:Professional, Enterprise, and Enterprise Advanced are all sold as prepaid annual seat-based subscriptions with no published flat pricing, and every quote requires a sales conversation, unlike Stoat's fully free plan with zero tiers to negotiate
Pros
- Self-hosted core is free (MIT-licensed) with no user limit, avoiding SaaS vendor lock-in.
- Deployment options (on-premise, private cloud, air-gapped) support compliance needs that pure-SaaS chat tools can't meet.
- Native apps across web, Windows, macOS, Linux, iOS, and Android.
- Open-core model means the underlying chat engine's code is auditable even though advanced features are commercially licensed.
Cons
- No published flat pricing for any paid tier; all require contacting sales and a prepaid annual commitment.
- Self-hosting the free core requires ongoing server maintenance, scaling, and upgrades.
- Advanced features (sovereign AI, high availability, air-gapped support) sit behind the commercial Enterprise license, not the open-source core.
- Smaller third-party app/integration ecosystem than Slack, which has a much larger app marketplace.
Pricing: Free — Free core self-hosted ($0) matching Stoat's plan; Professional/Enterprise/Enterprise Advanced are prepaid annual subscriptions with no published flat price, while Stoat has no paid tier to compare (verified undefined NaN, NaN)