If you have used an iPhone for any amount of time you quickly learn just how useless those 5 bar/dots really are when it comes to tell you how good of a cell signal you have. Most people don’t know that there is actually a way to change those 5 bars/dot into a precise number that will show you the exact cell signal strength. It takes less than a minute to do and even allows you to easily switch back to the traditional dots if you want. Here are the steps
1.) Dial *3001#12345#*
Launch you phone app, pull up the keypad, dial *3001#12345#* and hot the green call button
2.) iPhone will enter Field Test Mode
Your phone will then go into Field Test mode and you will see in the upper left hand corner that your reception strength will change from dots to a number
3.) Hold down the Power/Lock button until you see the Power Down screen
Hold down the Power/Lock button located on the side of the iPhone 6 or the top on older models and NOT the round Home button on the front of the phone. Keep the button pressed until you see the Power Down screen but do not turn the phone off.
4.) Hold the Home button down for 6 seconds
When you see the Power Down screen hold down the round Home button on the front of the phone down for about 6 seconds.
5.) You are done
You will see the phone go back to the home screen and you are done. Should you want to change the display from the number back to the dots simply tap on the number to flip back and forth between the two.
The signal strength will then be displayed as a negative number and the closer the number is to 0 the stronger the signal is. A number between -35 and -70 is a strong 5 dot signal and anytime lower than -100 is a 1 dot signal.