GrabDiff / comparisons
GrabDiff vs Uptime Kuma
Last reviewed May 2026. Pricing from public sources; verify before buying.
Uptime Kuma is an excellent self-hosted uptime monitor. It is free, open source, runs in Docker, and covers HTTP, TCP, ping, DNS, push (heartbeat) monitoring, and status pages. A lot of people use it. The main things it does not do: take scheduled screenshots and diff them, and run without a server you manage yourself.
Feature comparison
| Feature | GrabDiff | Uptime Kuma |
|---|---|---|
| HTTP uptime checks | Yes | Yes |
| Screenshot + pixel diff | Yes | No |
| TCP / ping monitoring | Yes (TCP port) | Yes |
| DNS monitoring | No | Yes |
| Cron heartbeat / push monitor | Yes | Yes |
| SSL expiry alerts | Yes | Yes (basic) |
| Domain expiry alerts | Yes | No |
| Status pages | Not yet | Yes |
| Hosted (no infra) | Yes | No (self-hosted) |
| Cost | Free to $19/mo | Free (your server costs) |
| Open source | No | Yes (MIT) |
Where Uptime Kuma wins
Free forever, including for unlimited monitors. No third party holds your monitoring data. Runs on a $5/mo VPS or a Raspberry Pi on your desk. Status pages are built in. DNS monitoring. Docker monitor. Game server monitor. If you are already running a server and you want a simple, no-cost uptime monitor you can trust, Uptime Kuma is hard to argue with. The community is large and the project is actively maintained.
Where GrabDiff wins
Visual screenshot diffs. Uptime Kuma does not take screenshots. It will not tell you your React app is serving a blank page or that your homepage layout broke after a deploy. GrabDiff runs headless Chrome, screenshots every monitored URL on a schedule, and diffs each one against the last known-good baseline. That is the gap.
GrabDiff is also hosted. You do not need to run a server, keep it updated, or worry about your monitor going down because the machine you run it on goes down. If you use Uptime Kuma to monitor your production server but both are running on the same VPS, there is a gap there.
Which to use
Uptime Kuma if you want free, self-hosted, open-source monitoring and you are happy managing the infra. GrabDiff if you specifically need visual screenshot diffs or want a hosted service where you do not manage anything. They work well together: Uptime Kuma for HTTP and ping checks across everything you run, GrabDiff for the URLs where you need to know if the page looks right.