I have covered the macOS Wireless Diagnostics App in a previous article. However, I only covered the Default testing method. There are other, more granular ways to use this utility that reveal more information. If you are having WiFi problems, or if you just want to be well armed for future WiFi problems, read on.
As stated in my previous article you access Wireless Diagnostics by holding down the Option ⌥ Key and selecting the WiFi symbol in your menubar. If you do not keep WiFi in your menubar you can access the actual Wireless Diagnostics App here: /System/Library/CoreServices/Applications. When you first open Wireless Diagnostics you will be at this window:
You can click on the “Continue” button to be taken through the Default, Canned checking procedure. However, if you click on the Window Menu there are more interesting, helpful features:
The “Assistant” is the main window you just left, so start with “Info”:
You can go over some information of your network here. My network Quality is rated as “Excellent” which is good to know.
Next, select the “Scan” feature:
Had to block out some information here to protect the innocent. The Scan feature shows you the WiFi networks in your area including your own. There are third party programs that perform some of these features with more detail, but I would just stick with Apple’s Wireless Diagnostics App and see if it is adequate for your needs.
Lastly, select the “Performance” feature:
If you look closely you can see that my Signal Strength is strong, but Noise is low which is good. The Quality is pretty good as well. If you were having WiFi problems the Quality and Signal Strength would register much lower.
The Wireless Diagnostics App is just another in a long list of helpful Apps included in the macOS. While this article and these images are from the Mojave version of the App, you can access it in most of the recent macOS versions. It can be helpful if you are attempting to diagnose WiFi problems. Even if you are not having WiFi problems, it would not hurt to have a look around inside the App to familiarize yourself with what is there.