Uptime Kuma

Uptime Kuma monitors your websites, APIs, and services and notifies you immediately via Slack, Discord, Telegram, email, or 90+ other channels when something goes down. Self-hosted, beautiful UI, dead simple setup.

MIT license. Install it with Docker in one command, add your URLs, set check intervals, and you're monitoring. The dashboard shows uptime percentages, response times, and certificate expiry. You can share public status pages with your users, like those "status.yourcompany.com" pages, but free.

Everything is free. No paid tier, no cloud version, no premium features. One developer (Louis Lam) built and maintains the entire thing. The community is massive and active.

The catch: Uptime Kuma monitors from one location, wherever you host it. If your server is in US-East and you're checking availability from there, you won't know about regional outages in Europe or Asia. Paid services like Better Stack or Pingdom check from multiple global locations. Also, if the server running Uptime Kuma goes down, your monitoring goes down with it. For production services, consider running it on a separate provider from what you're monitoring.