Server monitoring tells you when a website or service goes down, often before visitors or clients notice and report the problem.

Uptime Kuma is a popular free, self-hosted monitoring tool with a clean dashboard, multiple check types, and notification support.

It can monitor HTTP websites, TCP ports, DNS records, and other services at intervals you choose, recording uptime history for each.

Notifications via email, messaging apps, or webhooks alert you immediately when a monitor fails, so you can respond quickly.

Running monitoring on a separate server from the services it watches is important, so a single server failure does not silence your alerts.