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Simple WiFi strength indication on Mac OS X

I recently had to investigate WiFi connectivity troubles. To quickly know the current quality, I was looking for a strength indicator app that sits in the status bar. I found this very simple one to be very useful, despite the mediocre rating.

In the preferences, I have set the Maximum Signal-to-Noise Ratio (SNR) to 25 dB and the refresh interval to 2 seconds. Also, I’ve added it to the login items of my user account. This will make the status bar show “100%” in most cases (at least 54 Mbps throughput possible) but will drop if the WiFi signal quality is really bad.

25 dB is the lower end of “very good signal” according to common knowledge in the real world. Here is an example of a categorisation, blatantly stolen from wi-fiplanet.com:

  • > 40dB  SNR = Excellent signal (5 bars); always associated; lightening fast.
  • 25dB to 40dB SNR = Very good signal (3 – 4 bars); always associated; very fast.
  • 15dB to 25dB SNR = Low signal (2 bars); always associated; usually fast.
  • 10dB – 15dB SNR = Very low signal (1 bar); mostly associated; mostly slow.
  • 5dB to 10dB SNR = No signal; not associated; no go.