head to head · open source
Uptime Kuma vs cortex
Uptime Kuma has 91,498 GitHub stars, 8,431 forks, 805 open issues and last shipped today. cortex has 5,863 stars, 877 forks, 343 open issues and last shipped today. Uptime Kuma leads on adoption by 1,461% (91,498 vs 5,863 stars). Uptime Kuma is written in JavaScript under MIT; cortex is written in Go under Apache-2.0. Uptime Kuma has attracted 9% as many forks as stars, cortex 15%. cortex 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 | cortex | |
|---|---|---|
| GitHub stars | ★ 91K | ★ 5.9K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Go |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 8.4K | ⑂ 877 |
| 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 cortex if
- You want the cortex 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 cortex 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 cortex
Cortex is a horizontally scalable, highly available, multi tenant, long term storage backend for Prometheus and OpenTelemetry Metrics, aimed at platform and observability teams whose metrics workload has outgrown a single Prometheus server.
read the full cortex overview →
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Frequently asked questions
Is Uptime Kuma or cortex more popular?
Uptime Kuma has 91,498 GitHub stars and cortex has 5,863. Uptime Kuma has the larger community by that measure.
Are Uptime Kuma and cortex free?
Both are open source. Uptime Kuma is licensed under MIT and cortex under Apache-2.0. Neither carries a licence fee.
What is the difference between Uptime Kuma and cortex?
Uptime Kuma is written in JavaScript and cortex 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 cortex?
Choose Uptime Kuma if you want the larger community (91,498 stars) or its MIT licence terms. Choose cortex if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.