iPhone dBm
iPhone iPhone iOS 9
Lastmod: 2015-08-15

iPhone: Ever feel tricked by your phone’s signal bars into thinking you have a better reception that you actually do?

This simple hack will transform those bars to show the actual signal in decibels (dBm). No jailbreaking is required and it’s reversible.


  1. Dial 3001#12345# on your iPhone then press Call.
  2. You’ll now enter Field Test mode. You’ll notice a signal strength indicator on the upper left hand corner of your screen. You can toggle between signal strength bars and a number by simply taping on it. At this point, press the home button to exit the app or if you would like the feature to be permanent, continue on. Don’t worry, the process is completely reversible.
  3. Hold down on the Power button until you see the ‘slide to power off' bar. Do not power off the device.
  4. Press down on the Home button until the app closes and you return to your home screen.

This will last across restarts. The lower your number, the stronger your signal —but don’t include the - sign when evaluating (so, if the signal says -60, that’s better than -90).

Return Default

  1. Dial 3001#12345# on your iPhone then press Call.
  2. Press on your Home Button once.