Uptime Kuma is a free, open-source uptime monitor that you run yourself. It's self-hosted, so you need your own server or a Docker host to install it on. It's for technical founders who like owning their tools and don't mind a little setup. The software is free under the MIT licence. Your only cost is the server it runs on.
What it can do for you
It checks HTTP(S) sites, including looking for a keyword or reading a JSON response, plus TCP ports, websockets, ping and DNS records. It can also watch Docker containers and Steam game servers. Push checks cover scheduled jobs: your job pings Uptime Kuma, and you're told if it stops. Checks can run as often as every 20 seconds.
Alerts can go by email or through more than 90 notification services. You can publish several status pages, and it shows certificate information for your sites. Mobile apps aren't named, but you can watch an app's backend with a push check.
Why it stands out
Monitors are only limited by your server, checks are fast, and the alert options are wider than any hosted free plan we compared on 26 Oct 2026.
The honest downsides
- Self-hosted. You install it, update it and keep it running.
- Host it somewhere else. If it runs on the same server as your site, both can go down together and you won't get the alert.
- Domain expiry alerts aren't mentioned.
Skip it if
- you don't have, or don't want, a server to look after
- you want someone else to keep the monitor running
Alternatives
- Better pick if you don't want to run a server: HetrixTools. It's hosted and free for 15 sites at 1-minute checks, with SSL, domain and nameserver alerts. The catch: you must log in every 90 days.
- Upptime is also free and open source, but runs on GitHub, so there's no server to manage.
Some links may be affiliate links. They help keep WebTools.directory running at no extra cost to you.
Comments