TCP port testing links for convenience

The site provides a valuable service for free: the server listens an almost all TCP ports and replies with a simple HTML if the request was successful. You can use this to test whether something between a client and this server filters access to certain ports.

If you're testing from a browser, keep in mind that they block access to certain ports as well.
Chromium's list:
Firefox's list:

The latter is an extension of the Chromium list by adding the 4160 and 6679 ports.

If you want to do some testing from a browser, here's a list of links that you just have to click. Smile
Note that applies rate limiting on the source IP addresses so clicking through all of these in a single session won't work.

This is a list of some well-known ports (from that are not on the browser restricted list.
The following list contains a link for every 100 ports under 1024 and a link for every 1000 ports above 1024.