head to head · open source
Uptime Kuma vs alertmanager
Uptime Kuma has 91,498 GitHub stars, 8,431 forks, 805 open issues and last shipped today. alertmanager has 8,613 stars, 2,469 forks, 419 open issues and last shipped yesterday. Uptime Kuma leads on adoption by 962% (91,498 vs 8,613 stars). Uptime Kuma is written in JavaScript under MIT; alertmanager is written in Go under Apache-2.0. Uptime Kuma has attracted 9% as many forks as stars, alertmanager 29%. Uptime Kuma 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
| Uptime Kuma | alertmanager | |
|---|---|---|
| GitHub stars | ★ 91K | ★ 8.6K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Go |
| Last push | 2026-09-18 | 2026-09-17 |
| Forks | ⑂ 8.4K | ⑂ 2.5K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Uptime Kuma if
- You weight community size — 91K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick alertmanager if
- You want the alertmanager feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Go
- You evaluated both and alertmanager fits your workflow better
About Uptime Kuma
Uptime Kuma is a free, MIT licensed, self hosted monitoring tool with a reactive web dashboard, built for operators and teams that want to watch their own HTTP, TCP, and DNS endpoints and keep the resulting data on their own infrastructure.
read the full Uptime Kuma overview →
About alertmanager
Prometheus Alertmanager is the Go based, Apache 2.0 alert routing service that receives alerts from client applications such as the Prometheus server, deduplicates and groups them, and routes them to receivers including email, PagerDuty, OpsGenie, Slack and a generic webhook — it is for operations and platform teams that already run Prometheus and need notifications that are neither duplicated nor noisy.
read the full alertmanager overview →
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Frequently asked questions
Is Uptime Kuma or alertmanager more popular?
Uptime Kuma has 91,498 GitHub stars and alertmanager has 8,613. Uptime Kuma has the larger community by that measure.
Are Uptime Kuma and alertmanager free?
Both are open source. Uptime Kuma is licensed under MIT and alertmanager under Apache-2.0. Neither carries a licence fee.
What is the difference between Uptime Kuma and alertmanager?
Uptime Kuma is written in JavaScript and alertmanager 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, Uptime Kuma or alertmanager?
Choose Uptime Kuma if you want the larger community (91,498 stars) or its MIT licence terms. Choose alertmanager if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.