How to Make Full-Screen Calls to Xiaomi: The Complete Guide

Owners of modern Xiaomi smartphones often face visual discomfort during calls. Instead of seeing a full subscriber image or a high-quality background, users observe black bars from above and below the screen. This problem is especially relevant for models with elongated displays and an aspect ratio of 18:9 or 20:9. Standard settings of the MIUI shell or HyperOS do not always automatically determine the correct display mode for the Phone application.

The solution lies in hidden developer menus or special engineering codes that allow you to force the change of application scaling. Enabling the Full Screen Mapping mode for calls does not affect the quality of communication, but only changes the visual component of the interface. In this article, we will discuss in detail the secure methods of expanding the call area that are suitable for most current models of Redmi and Xiaomi.

Before we make any changes, we need to understand that the call interface is a system application that is default-proof against random modifications. However, using the standard debugging tools, you can bypass the scaling limitations. It is important to act consistently so that other system functions do not disrupt.

Causes of black stripes when calling

The main reason for the incorrect display of the call interface is the desynchronization of the application resolution and the physical resolution of the smartphone matrix. When developers create a shell, they lay certain proportions, but in new models the screens become more elongated. The system by inertia runs the application in standard 16:9 mode, leaving unused space black.

Another factor is the optimization of the theme itself. Some third-party themes downloaded from the MIUI Themes store can force their indentation settings. This causes even native Xiaomi models to make the call interface look compressed, and the problem is common after major Android updates, when system files are rewritten and the app cache is not cleaned correctly.

It is worth noting that on models with a cutout in the screen (" bangs") or a hole under the camera, the system can automatically add indents to avoid overlapping the dynamic elements of the interface, in some cases this is a software error that can only be fixed manually through the developer menu.

⚠️ Attention: Changes to the developer settings can lead to unstable interface operation. Before the manipulation, it is recommended to back up important data.

Activate the developer menu on Xiaomi

To access the necessary scaling options, the first step is to turn on the developer mode, which is a hidden section in the settings, designed to debug applications, but contain useful features for advanced users. Without activating this mode, the desired items will simply not appear in the menu of the smartphone.

The activation process is standard for all Android devices, so you need to go to the basic settings and find information about the version of the system, then you need to click on the build number several times until the system notifies you of the successful activation.

• 📱 Open “Settings” and go to the “About Phone” section».
• 👆 Find the line "Version" MIUI» (or "Version" OS») And press it fast. 7-10 successively.
• ✅ Wait for the pop-up notification “You became a developer!».
• 🔙 Return to the main settings menu and select “More» → «For developers».

After you do this, you'll see a new item in the settings menu, and inside of it are the keys that allow you to control the behavior of applications. Be careful not to change the other settings in this section unless you're sure they're going to work, because it might affect your Bluetooth or your app. USB-debugging.

Set up full screen mode through the debugging menu

The most effective way to stretch the call interface is to use Minimum Width or Forced Full-screen display, and Google has introduced more flexible settings for specific applications in new versions of MIUI and HyperOS, avoiding a global change in screen resolution.

You need to find a section on the developer menu that's related to the display, which can be called Forced Full-screen Display or Display size. If you change the Global Minimum Width (DPI), it will affect all the icons and text in the system, which can make the interface too small, so you'd better look for an application-specific setting.

The algorithm of actions is as follows:

• 🔍 In the “For Developers” menu, find the “Forced Full-screen” option).
• 📞 In the list of applications, find “Phone” or “Contacts».
• ✅ Activate the switch opposite the selected application.
• 🔄 Reboot your smartphone to apply changes.

If your firmware version doesn't have the option of selecting a specific application, you can try changing the Smallest width setting. Write down the original value (usually 360 or 392 dp) to be able to go back. Increasing this value by 10-20 units will visually stretch the content, but can make the font too small.

Using CIT engineering code

An alternative method that often works where developer settings are powerless is the CIT (Customer Integration Test) menu, a diagnostic tool built into Xiaomi firmware that can test the sensor and display, and sometimes reset display settings.

To enter the test menu, a special set of characters is used in the call app. Enter the following code:

##6484##

Once you enter the last character, you'll see a list of tests, and we're interested in checking the display, and you'll find Display or LCD and run the test. While direct resolution changes are rare here, resetting the color or sensor calibration in this menu sometimes eliminates software bugs that cause black bars.

⚠️ Note: Do not try to change the settings in other sections. CIT, If you don't know their exact purpose, recalibrating the sensor may require recalibrating the sensitivity of the screen.

It’s also worth checking if Pocket Mode is enabled with aggressive settings, which can darken the edges of the screen, as checked in the same CIT menu under the “Proximity sensor” section.

Comparison of scaling methods

The choice of method depends on the version of your operating system and the specific model of the smartphone. Different methods have their advantages and risks. Below is a table that helps you choose the best way to solve the problem.

As you can see from the table, the safest and most effective way is to use the built-in forced display function for a particular application. Changing the global DPI (point per inch) carries risks, since after resetting settings or updating the firmware, the interface can “go” and it will be more difficult to return everything back without writing down the original values.

Compatibility issues on different versions of MIUI

Users often notice that on global versions of firmware (Global) ROM) Black stripes are less common than in Chinese (China) ROM) This is because the Chinese versions originally have different interface standards that don't always adapt properly to European screens.

In addition, the Google Caller itself, which is now installed by default on most Xiaomi devices, has its own scaling algorithms. In some cases, updating the Phone app through the Google Play Market solves the problem automatically, as developers add support for new screen resolutions.

If you have a custom theme, try temporarily switching to a standard theme “Classic” or “System”. Often it is the graphic elements of the theme (answer buttons, background) that have rigidly defined dimensions that do not stretch to the entire screen.

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Before you change your system settings, try simply clearing the Phone and Contacts app cache through the Apps menu» → «All applications. 15 percent of the time, this solves the problem without tampering with deep system settings.

Return to standard settings

If you realize after the changes that you don't like the full screen or the interface is not readable, you need to put it back, and ignoring this step can cause some controls to go beyond the visible area of the screen.

To undo the changes, go back to the Developer Menu, find the item you previously activated ("Forced Full Screen Display" or "Minimum Width"), turn off the switch or return the original DPI value you wrote down before starting the experiments.

Once you reset, make sure to reboot the device, which is a critical step, because the SystemUI graphics shell only loads the resolution settings when you start the system, and without rebooting, the changes may not be applied correctly.

⚠️ Note: If you have changed the value of "Minimum width" and the screen is unreadable, and you can not enter the settings, try connecting to your computer through the device. ADB (Android Debug Bridge and enter the command to reset: wm size reset.

Frequently Asked Questions (FAQ)

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The safest way to remove black bars is to activate forced full-screen display for the Phone application in the developer menu without changing the global DPI parameters of the entire system.