$ http
Website Availability Test
Free, no signup. Runs from our distributed probes — see how your site looks from different parts of the world.
What is a website availability test?
The test requests your URL the way a browser would: resolve DNS, open a TCP and TLS connection, send an HTTP request and read the response — reporting the status code and a timing breakdown for each phase.
Run from multiple regions, it answers the question a single ping can't: is the application actually answering users, everywhere?
How to read the results
- Status 2xx or expected 3xx means up; 4xx points at configuration or auth; 5xx means the server answered but the application failed.
- The timing breakdown localizes slowness: long DNS = resolver problem, long connect = network path, long first byte = the server itself.
- Down from one region with the rest healthy is a network, CDN or geo-blocking issue — your server is fine, but users there still can't reach you.
Questions
FAQ
What counts as "up"?
The host answered with an HTTP response and an expected status code within the timeout. A monitor can be stricter: require a keyword in the body, or a specific status.
Why does only one region fail?
Regional routing incidents, CDN edge problems and geo-blocks all produce exactly this pattern. It's the most common kind of outage that single-server monitoring never sees.
How is this different from ping?
Ping proves the machine is reachable via ICMP. The HTTP check proves the application answers real requests — a server can respond to ping perfectly while the app behind it is down.