Find the best Wi-Fi channel

Funkblick counts the networks per channel and picks the quietest.

Free, Android 8.0 or newer, runs on GrapheneOS without Google services. No account.

Wi-Fi channels: suggestion channel 13 and 40, bar chart of networks per 2.4 GHz channel

Funkblick is a Wi-Fi analyzer: Android shows it every network in range, and Funkblick counts them per channel, weighs them by signal strength and suggests the quietest 2.4 GHz and 5 GHz channel for your own router.

Set it on your router

Start the scan in Funkblick and open Wi-Fi channels for your router under More. Best where your Wi-Fi is weak.
Note the suggestion for 2.4 and 5 GHz.
Open your router’s web page, usually printed on its label, and find the radio or channel settings.
Enter the channel, save, and check again in Funkblick after a few minutes.

Questions

Which 2.4 GHz channel is best?

Usually 1, 6 or 11, because they don’t overlap. In Europe 13 is allowed too and often empty. Funkblick weighs the neighbours by signal strength and picks one.

What is DFS?

5 GHz channels 52 to 144 are shared with weather and other radar. A router has to listen for a minute before it uses them and must switch away when it hears radar. They are often quiet for exactly that reason.