Checking if web server is online/offline

javascript jquery jqxhr
Nathan picture Nathan · Jun 2, 2014 · Viewed 11.2k times · Source

How would I check if a web server is online/offline from my domain? I've already tried an $ajax call with jsonp, but if the server isn't responding with json, then that doesn't work. Is there any other way to get an http response from a server?

Answer

Jack_of_All_Trades picture Jack_of_All_Trades · Jun 2, 2014

Just copied shamelessly from one website for easiness:

<img src="http://site-to-check.com/online.png" alt="status" onerror="this.src='files/offline.png'" />

The setup is:

An online icon (online.png) on the remote server you want to see the status of. An offline icon (offline.png) on the server that is going to show the status page.

If the image on the remote server fails to load, the onerror event is triggered and the javascript rewrites the image tag to show the offline image. You can use relative or absolute paths for the offline image. This snippet is fully compatible with all major browsers, including Internet Explorer down to version 5.5!

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