head to head · open source
Mattermost vs certspotter
Mattermost has 39,510 GitHub stars, 9,087 forks, 1,012 open issues and last shipped yesterday. certspotter has 1,195 stars, 104 forks, 18 open issues and last shipped 5 days ago. Mattermost leads on adoption by 3,206% (39,510 vs 1,195 stars). Mattermost is written in TypeScript under a custom or non-standard licence; certspotter is written in Go under MPL-2.0. Mattermost has attracted 23% as many forks as stars, certspotter 9%. Mattermost was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
← all 20902 open source comparisons
Side by side
| Mattermost | certspotter | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 1.2K |
| License | Custom / other | MPL-2.0 |
| Written in | TypeScript | Go |
| Last push | 2026-11-02 | 2026-10-29 |
| Forks | ⑂ 9.1K | ⑂ 104 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mattermost if
- You weight community size — 40K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick certspotter if
- You want the certspotter feature set and don't need the biggest community
- You prefer the MPL-2.0 license terms
- Your stack matches Go
- You evaluated both and certspotter fits your workflow better
About Mattermost
Mattermost is an open core, self hosted collaboration platform that offers chat, workflow automation, voice calling, screen sharing, and AI integration. This repo is the primary source for core development on the Mattermost platform; it's written in Go and React, runs as a single Linux binary, and relies on PostgreSQL. A new compiled version is released under an MIT license every month on the 16th. Deploy Mattermost on premises, or try it for free in the cloud. Learn more about the following use cases with Mattermost: DevSecOps Incident Resolution IT Service Desk Other useful resources: Download and Install…
read the full Mattermost overview →
About certspotter
Cert Spotter Certificate Transparency Monitor Open Source Edition Cert Spotter is a Certificate Transparency log monitor from SSLMate that alerts you when an SSL/TLS certificate is issued for one of your domains. Cert Spotter is easier to use than other open source CT monitors, since it does not require a database. It's also more robust, since it uses a special certificate parser that ensures it won't miss certificates. Cert Spotter is available as a hosted service by SSLMate that also provides monitoring for expiring and incorrectly installed certificates, Slack notifications, and a Web dashboard for tracking…
read the full certspotter overview →
More in Security & Privacy
Related comparisons
More Data Security & Privacy projects
Compare either of these against the rest of the Data Security & Privacy field.
Frequently asked questions
Is Mattermost or certspotter more popular?
Mattermost has 39,510 GitHub stars and certspotter has 1,195. Mattermost has the larger community by that measure.
Are Mattermost and certspotter free?
Both are open source. Mattermost has no licence declared in this registry, and certspotter is licensed under MPL-2.0. Both are free to self-host.
What is the difference between Mattermost and certspotter?
Mattermost is written in TypeScript and certspotter in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mattermost or certspotter?
Choose Mattermost if you want the larger community (39,510 stars) or its Custom / other licence terms. Choose certspotter if its feature set, stack or MPL-2.0 licence fits better. Both are self-hostable.