Hidden iPhone App: Secret Feature Shows In-Depth Info About Your Device, Here's How to Unlock It

Did you know that there's a hidden app on iPhone? This app lets you view the complete information of your device.

Developers and smartphone operators often use this iPhone secret feature to quickly scan critical information like LTE, UMTS and GSM functionality.

Sources from MacRumors call this app the hidden Field Test Mode. This feature is present in some iPhone devices running on iOS 13, 14 and 15.

How to Activate Hidden iPhone App: Field Test Mode

TikTok user Frank McShan shared the steps on how to activate the hidden iPhone app in a quick video. According to McShan, you must first open the Phone app. Then you should input the code "*3001#12345#*" and click on the phone button. This command will not make a call, but instead, open the Field Test App.

What Is Field Test Mode: The iPhone Secret Feature

Field Test Mode is primarily used to check on cellular signal and connection. It specifically converts the cellular signal bars to numerical measurement which engineers can analyze. The data can be seen by entering the "Dashboard."

According to MacRumors, the measurements will read "rsrp0" and "rspr1," corresponding to the signal strength in decibel-milliwatts. The numbers are always negative, and the lower number represents a stronger connection.

For reference, the numbers range between -50 to -130. Numbers close to -50 indicate strong signal strength, while numbers close to -100 indicate poor connection and slower data speeds.

As previously mentioned, the hidden feature is primarily made for operators, so it is not necessary for daily use. However, it is still a pretty cool feature to show off to friends who might not know about it.

iPhone Secret Feature Issues

It should be emphasized that not all iPhone devices support the hidden Field Test Mode. MacRumors pointed out the numerical measurements are no longer necessary for the recent versions of iOS and might be discontinued by developers.

However, contrary to their expectations, the iOS 14 updates introduced a new design for the Field Test Mode. This upgrade also extended to the current iOS 15. This implies that recent iPhone releases might still support the Field Test Mode.

Overall, Field Test Mode is an extremely helpful feature to anyone who might recognize its purpose. This hidden app will quickly scan your device for its cellular performance, which can help you pick the best location for a good connection.

Note that this is only one of the many hidden features available on the iPhone. In fact, iPhone also has hidden features for adding background music while scanning, real-time translation, a recovery contact and customizable text size. More information on the topic is found in this article.

With 2022 just around the corner, Apple bring other exciting updates to iPhone soon. Fans are recommended to watch out for announcement which could drop anytime this month.