I’m sure everyone who has ever used a cell phone has in some point in time struggled with signals and have raised their iPhone 4 / 4S / 3S  to the skies or have even thrown it into the air to get a text message or call through. These are times when our signal meters fail and we just wander away not knowing which direction would improve the signal strength.

iphone signal strength number

How to test the true Signal Strength of your iPhone 4S / 4 / 3GS

The signal bars are not that accurate and we have a really cool tip for all you iPhone users that will enable you to change your signal bar into actual numbers. The numbers are in decibels and the closer you are to Zero the better will be the signal strength.

iphone signal strength code
Field Test iPhone Signal Strength

Now, this trick does not require any downloads or anything, nor does it require a jailbroken iPhone. Just follow the steps below and you will have a whole new way of checking out your signals.

Step 1: Type in *3001#12345#* on your iPhone’s keypad and press call.

Step 2: You have now entered field test mode, just tap on the signal indicator on the top left of the screen and you will be able to toggle between signal bars and decibel numbers. (Remember the closer you are to Zero the better the signals).

Step 3: Hold down the power button until you see the “slide to power off bar”, however do not power off your device.

Step 4: Keep pressing the home button until the screen closes and return to your homescreen.

That’s all there is to it! Even when you restart your iPhone you will still be able to toggle between bars and numbers! Pretty cool eh?

Read Also: Best WIFI Signal Strength Meter Apps for iPhone

To take your iPhone back to its default mode, you just have to type in *3001#12345#* on the keypad and press call. After that, press your home button once and your default settings will come back and you will not be able to toggle between bars and numbers any more, the standard bar will re-appear.

Be sure to try this out and let us know!

  • Jacob Benavides

    I have this enable long time ago and I prefer this singal meter than anything. Ps could you use the spotlight search just to get to the field test.

  • Toastmaster Mike

    I think this is BRILLIANT! I’d just like to know what are the numerical parameters for best (0?) and worst signal. Anyone know?

  • UnlockBoot

    It also works on iOS 6.1

  • RRWD

    Doesn’t work on ATT iOS 6.1.2. Gives message: Error performing request.

  • UnlockBoot

    Try again. It works with ANY iOS software version.

  • Sarah Baldwin

    Worked for me on my Verizon iPhone 5. Helped me determine that even with LTE turned off, my iPhone 5 is not pulling as much signal as my colleagues iPhone 4S. But with LTE turned off, I am getting a much stronger signal. Thanks for sharing!

  • Brihoppy

    Tried but defaults straight back to signal strength indicator..?!?

  • KC4SW

    This works but, make sure Siri is disabled. Holding the Home key down activates Siri and does not allow the hack to complete

  • Sadush Meti

    Or just open SBSettings drop window and click on processes and close field test and you go directly to your springboard and number still there it works I have try it

  • MK

    ,hi i hve done it on my iphone 4s 9.3.5… it is works on it but it shows the signal strenth in -94. and i cant call any one, because it shows call failed. please help me to fix this problem