Wi-Fi Diagnostics is an incredibly useful utility to troubleshoot and optimize any wireless network and the signal strength of computers that are connecting to it. This utility first came bundled in Mac OS X Lion and works with all wireless routers and not only the Apple branded ones, meaning you can improve the performance of just about any wifi network by using it and making some adjustments along the way. It’s easy to use and we’ll walk you through the process of getting the best wireless signal using the app, but first we have to uncover the tool itself.

The Wi-Fi Diagnostics app is buried within Mac OS X 10.7 & OS X 10.8, here’s how to access it:

From the OS X desktop, hit Command+Shift+G and enter the following path:

/System/Library/CoreServices/ Sort alphabetically and find “Wi-Fi Diagnostics”, if you plan to use the app even somewhat frequently it’s recommended to drag Wi-Fi Diagnostics into Launchpad for easy access

With Wi-Fi Diagnostics now in the easier to access Launchpad… open Wi-Fi Diagnostics.app, then:

For OS X Lion users, check the radiobox next to “Monitor wireless performance” then click on the “Continue” button

For OS X Mountain Lion (and later) users, pull down the “View” menu and choose “Performance”, or just hit Command+5

Why Apple changed the process between OS X 10.7 and 10.8 is a mystery, but the feature remains in the newest versions of Mac OS X regardless. Anyhow…

Now is when the fun begins. The chart you see is a live wireless signal strength and noise meter, you want the yellow signal strength bar to be as high as possible. Pay attention to the green line of noise as well, you want that to be as low as possible in relation to the yellow line of signal strength.

If the signal strength is high and noise is low, you’re already good and you don’t need to change much. For most of us, signal will be lower than we want it to be, depending on where the wireless router is stored in relation to our computer gear.

Here are some tips to try out and to improve signal strength, keep an eye on the signal as you make adjustments:

Tweak the physical antennas on the wireless router and aim them in different directions

Move the wireless router away from walls, fireplaces, etc – even just a foot or two of space can make a big difference

Move the wifi router away from TV’s, microwaves, refrigerators, and other electronics that may interfere with signal

Relocate the Mac in relation to the router, this is obviously easiest with a MacBook Air or Pro

Consider changing Wi-Fi network channels if there are many matching channels from nearby routers

Once you have arrived at a reasonable compromise to how your hardware is physically configured and the resulting signal strength, enjoy your newly optmized wifi network.

Some important things to remember here: not all internet connections are capable of transferring data at optimum wireless speeds, so you may not notice much of a difference in internet connectivity speed if any at all with these adjustments. This basically means that a weaker wireless signal may be more than adequate to transfer data at your ISP’s maximum bandwidth. Regardless, you’ll want the noise level to be as low as possible, since large amounts of wifi network noise can result in lost packets, reduced speeds, quirky behavior, random wireless connection dropping, and a variety of other problems.

If a wireless network is configured well and you continue to have problems with connectivity, check out some of our past articles on resolving such issues:

Using Wi-Fi Diagnostics I discovered my wireless signal to be much weaker when keeping the wifi router out of sight behind an LCD TV, simply moving the router away from the TV a few feet dramatically boosted signal strength. Run the app yourself and see what kind of performance boost you can get by adjusting your own wifi network.