How to unlock hidden features for the iPhone

The iPhone can do more than you expect – without any hacks or apps. Behind various key combinations are secret menus and displays, which are actually intended only for technicians. TECHBOOK reveals the secret functions for you.

With this trick the battery lasts longer

Some SIM cards for the iPhone support a secret mode that saves power. IOS accesses only the SIM card, if it is really needed. You activate this feature using the dialpad in the phone app with the shortcut * # 746025625 #. Then you have to press the call button. Unfortunately, not every provider supports this feature. If the mode is not supported, the phone will return an error message.

Free up to 10 gigabytes of storage

With a simple trick, you can easily scoop massive amounts of memory on the iPhone – without erasing photos, music or videos. All you have to do is pretend to borrow a movie on iTunes. How the trick works in detail, read in this article.

Talk to the mailbox without calling

There are those moments when you call somebody and do not really want him or her to lose weight. But there is a way to talk directly to the other’s mailbox. Each provider has a specific code for this: Vodafone 50, T-Mobile 13 and O2 33 Willman now send a message to the O2 number of a friend, you first select the area code, then the appropriate code and then the rest of the number, about 017x -33-xxxxxxx. Then immediately the mailbox ran and you can leave a message.


Apple iPhone X (64 GB)

✔12 megapixel dual camera
✔Cable charging
✔Face ID for secure authentication

Thus, the reception strength tests exactly

Hidden in the iPhone is the so-called “Field Test Mode”. It provides details about connection quality and Wi-Fi encryption modes. The reception is specified in decibels and you can see with which radio masts the smartphone communicates. To open the mode just dial * 3001 # 12345 # * in the phone and call. The reception scale is shown at the top left and usually starts at -40. Everything from -110 is rather bad reception, at -120 the conversation will probably falter or break off.

Certain numbers allow you to retrieve secret functions.


The exact reception strength can also be permanently activated. To do this, open the Field Test Mode, then hold down the power button until the “Turn Off” button appears. Then press the home button until you land on the homescreen again. Voila!



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Improve the voice quality

With the EFR mode you can get the maximum voice quality for calls. EFR stands for “Enhanced Full Rate”. This mode is activated in the telephone via * 3370 #. Disable works with # 3370 #. Small disadvantage: The battery life drops slightly due to the higher voice quality.


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Save the last percent battery energy

The opposite of EFR mode is the so-called half-rate. The capacity of the radio network is optimized for calls, but the quality decreases. If you expect a long conversation and the battery is almost dead, the mode could help. To activate Half Rate, dial * 4720 # in the phone.