head to head · open source
Sentry vs Checkmk
Sentry has 44,806 GitHub stars, 4,857 forks, 2,265 open issues and last shipped today. Checkmk has 2,369 stars, 555 forks, 55 open issues and last shipped yesterday. Sentry leads on adoption by 1,791% (44,806 vs 2,369 stars). Sentry is written in Python under a custom or non-standard licence; Checkmk is written in Python under GPL-2.0. Sentry has attracted 11% as many forks as stars, Checkmk 23%. Sentry was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (monitoring), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Sentry | Checkmk | |
|---|---|---|
| GitHub stars | ★ 45K | ★ 2.4K |
| License | Custom / other | GPL-2.0 |
| Written in | Python | Python |
| Last push | 2026-09-20 | 2026-09-19 |
| Forks | ⑂ 4.9K | ⑂ 555 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Sentry if
- You weight community size — 45K stars and counting
- You want the Custom / other license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick Checkmk if
- You want the Checkmk feature set and don't need the biggest community
- You prefer the GPL-2.0 license terms
- Your stack matches Python
- You evaluated both and Checkmk fits your workflow better
About Sentry
Sentry is an open source debugging platform for detecting, tracing, and fixing software issues in real time. It lives in the developer infrastructure ecosystem and provides error tracking and performance monitoring across languages, frameworks, and runtime environments.
read the full Sentry overview →
About Checkmk
Checkmk is a comprehensive IT monitoring system for infrastructure and application monitoring across physical, virtual, containerized, and cloud environments. It is an open source Python project released under the GNU GPL v2, and it lives in the infrastructure monitoring and observability ecosystem. The project provides a central monitoring engine, a web based interface, and support for many official and community maintained plugins.
read the full Checkmk overview →
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Frequently asked questions
Is Sentry or Checkmk more popular?
Sentry has 44,806 GitHub stars and Checkmk has 2,369. Sentry has the larger community by that measure.
Are Sentry and Checkmk free?
Both are open source. Sentry has no licence declared in this registry, and Checkmk is licensed under GPL-2.0. Both are free to self-host.
What is the difference between Sentry and Checkmk?
Sentry is written in Python and Checkmk in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Sentry or Checkmk?
Choose Sentry if you want the larger community (44,806 stars) or its Custom / other licence terms. Choose Checkmk if its feature set, stack or GPL-2.0 licence fits better. Both are self-hostable.