Ports are the numbered doors on a server, and knowing which service lives behind which number is the difference between a clean firewall rule and a hole you will find out about later. 22 is SSH, 443 is HTTPS, nothing surprising, until the obscure ones show up.
Search hundreds of common port assignments and the services that use them. Consult it when writing firewall rules or reading a scan result, and the unknown numbers stop being mysteries that get left open.
Try it now: open the free tool, runs 100{ddff9936f8333f09603555df7bd6492034f3a4a35de784276d3cf3d66166a113} in your browser.
Bottom line: search the port before you open it, know the service.
Your turn: use the tool free here, no signup, nothing leaves your device.
How do you use Port Scanner Reference Guide?
Open the Port Scanner Reference Guide in your browser (Interactive directory of common TCP/UDP ports). Type or paste your input, adjust the options, and copy the result. Everything runs locally on your device with no account and nothing stored, so the three steps below take seconds even for confidential work.
- Paste the text you want to work with.
- Choose the transformation you need.
- Copy the result, or tweak the input to see it update live.
Try Port Scanner Reference Guide free. It opens right in your browser.