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Call this number from your iPhone, see what happens

Today we bring you a new curiosity . A secret application that the iPhone has hidden by default, and which we will show you how to access. We will also show you other little tricks with the phone’s keypad.

How to access the Field Test

Let’s start with the first thing. What is the Field Test ? This is a hidden application on the iPhone that gives us information about the status of the mobile network (such as coverage or which cell we’re using). And how can we access this tool?

Call this number from your iPhone, see what happens
Call this number from your iPhone, see what happens

This is a very simple thing. All we need to do is go to the application on Phone on our iPhone. There we’ll go to the section of Keyboard and enter the following number:

It should be noted that this must be done by dialing the numbers on the phone keypad, as in reality no call is being made . In other words, it’s just a code that will give us access to the application called Field Test , so it won’t work if we save the number as a contact and call it without typing it.

Code to access the secret app Field Test.

How to see our coverage level in numerical value

The first trick we’ll look at is how we see our coverage level . But we won’t see it as we’re seeing it now, with a series of dots, but in its numerical value . That is, we’ll see its value with real units .

To do this, we’ll use the app called Field Test that we’ve just learned how to open. But this before could be done directly by entering the app, as the usual iOS coverage indicator was replaced by the numeric one while the app was open. But now in iOS at the top right shows a shortcut to the previous app. Therefore, we won’t be able to see the numerical value there.

Field Test, the hidden application of iOS

So how do we do it? There is a very simple trick. You just need to open the app of Field Test as above. Next, we’ll press the standby button on the iPhone until the slider comes up to turn it off. Once it appears, press the home button until the shutdown button disappears and the iPhone’s main screen appears. Now you’ll see that on the top of the screen you have the numerical indicator of your coverage.

What if I want to see the dots again? Just click on the indicator and it will return to normal. And if we click on it again, the numerical value will appear again. And how do we do that if we don’t want it to appear again? Simply reopen the app for Field Test , or restart the iPhone.

How to interpret the numerical value of the coverage

And in what units are we being presented? This value is expressed in decibels-milli, i.e. dBm . This is a dimensionless, logarithmic unit widely used in signal processing and power electronics. But obviously I’m not going to give you a 1000 word article explaining what they are. Instead, I will tell you only what we are interested in.

See coverage level in dBm.

As we can see if we are a little bit rogue, the value that appears to us in negative. And how can we know if we have good coverage or bad? Our coverage will be better the higher that number is , that is, the less negative it is (closer to 0). On the other hand, if we have a very low number (with a high absolute value), for example, below -115dBm, our coverage will be poor.

The value is between -40dBm and -140dBm , so a value between -40 and -90 is fine.

Other codes we can enter on our iPhone

But that is not the only code we can enter on our phone’s keypad. Although not very popular, the application of Field Test is very useful, and gives a lot of data that we haven’t analyzed.

These are other codes, which although not so “powerful”, are also very useful:

Find out your iPhone’s IMEI

The IMEI is a number that identifies your mobile device. And why do we need this number? Well for example, if we want to free up our iPhone in case it is linked to a company.

This code can be obtained from the Information menu , but it is more curious to do so by typing in a code . And what do we have to put on the phone’s keypad?

Once we type in this number, we’ll get the number.

View your iPhone’s IMEI.

Calling with hidden number

We’ve seen it many times in the movies, but we don’t know how to do it. Well, now you do!

Just enter the code #31# , followed by the number you want to call. You can also make it permanent from the settings menu by disabling the “Show Caller ID” option . However, if it’s a one-off, it’s more convenient to use this code as a shortcut.

And does it work? From what we’ve been able to prove, it does work, although we didn’t test every possible case. However, this doesn’t guarantee that you can’t know the number . Your operator and the recipient’s operator will know who made the call.

More codes

These are only the most used , but there are more of these. For example, we have *33*PIN# to block all calls, or #33*PIN# to undo it. But we can’t explain them all in one article.

What do you think? What do you think of these tricks and curiosities?