Six Colors
Six Colors

by Jason Snell & Dan Moren

Childhood Cancer Awareness Month

This month, join us and Relay FM in supporting St. Jude.

By Dan Moren

Find the best Wi-Fi channel with Wireless Diagnostics

Wireless Diagnostics Scan

Pursuant to my earlier Wi-Fi troubleshooting post, Michael Birenbach suggested via Twitter using OS X’s built-in Wireless Diagnostics to find the best (i.e. most interference free) channel to use for your Wi-Fi network.1

The following instructions are for Yosemite, but the principles should be the same for most recent versions of OS X:

  1. Hold down the Option key on your keyboard.
  2. Click on the Wi-Fi menu in your menu bar.
  3. Choose “Open Wireless Diagnostics…”
  4. Click Continue.
  5. Enter your admin username and password.
  6. From the Window menu, choose Scan.

This will open up a window with a detailed amount of information about all the Wi-Fi networks in your vicinity, along with suggestions for the best 2.4GHz and 5GHz channels. Channel selection tends to be more of an issue with 2.4GHz networks, which have far fewer channels than 5GHz, and many of which overlap in terms of which parts of the wireless spectrum they actually use.

Changing your Wi-Fi channel varies depending on routers, but it’s generally pretty straightforward; you may need to consult your documentation. There’s plenty else to be gleaned from Wireless Diagnostics2, but much of it veers toward the technical side.


  1. Not convinced this was purely an issue of congested channels, but your mileage may, as ever, vary. 
  2. There’s a performance grapher, access to log files, and even a dedicated packet sniffer packed in here. 

[Dan Moren is the official Dan of Six Colors. You can find him on Twitter at @dmoren or reach him by email at dan@sixcolors.com. His latest novel, The Aleph Extraction, is out now and available in fine book stores everywhere, so be sure to pick up a copy.]

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