How to make a full screen call Xiaomi Redmi 9

Modern smartphones, including the popular Xiaomi Redmi 9, feature large 20:9 aspect ratio displays, creating unique interface design requirements. Many users, when they move from older devices, experience unusual behavior during incoming or outgoing calls. Instead of the usual interface that covers all space, a compact floating window appears on the screen, which can occupy only a small part of the display.

This behavior is not a mistake, but a feature of the MIUI shell, which tries to adapt applications to large-format screens. However, for most gadget owners, this mode is uncomfortable, as the reset or response buttons become too small and contact review is difficult. Fortunately, Android provides tools for forced scaling of applications.

In this guide, we will discuss in detail how to activate full-screen mode for the Phone application on your device. We will look at the standard system settings, the possibilities of a hidden engineering menu and alternative methods for solving the problem if the standard methods did not give the desired result.

Why not call the full screen on Xiaomi

The main reason for the small call window is the mechanism for adapting the Android interface to different screen diagonals. MIUI developers are implementing a floating window for calls, believing that this allows the user to multitask, but often this simply interferes with. The system mistakenly classifies the dialing application as a program that is not optimized for the current display resolution.

In addition, the interface can be affected by the installed themes. Third-party themes downloaded from the GetThemes store often contain graphic elements that conflict with standard zoom settings. In such cases, even if the desired settings in the system, the visual shell can ignore them, imposing its own style of displaying windows.

⚠️ Note: If you use a third-party theme, reset it to standard ("Classic") before setting up to eliminate interface conflicts.

Also, consider that different versions of MIUI firmware (Global, China, Russia) may have slightly different settings, and in some builds, the forced scaling option is hidden in the developer menu, while in others it is available in the basic screen settings.

Set up full screen mode in the developer menu

The most effective way to get the call app to stretch across the entire display is to use the hidden developer menu, and that's where the global zoom settings are for all installed applications, including system ones, and you need to activate the developer mode itself if it's not already on your Redmi 9.

Go to the basic phone settings and select About Phone. Find Version MIUI» And press it fast. 7-10 Once you have a "You've become a developer" notification, you can move to advanced system settings.

The main settings menu will have a new section called “Additional” or “Extended Settings” where you can select “Developers For” and scroll down to the “Applications” section and find “Forced Scaling” where you need to find the “Phone” or “Contacts” app on the list and turn on the switch opposite it.

Once this option is enabled, the system will force the call interface to stretch over the entire screen area, ignoring standard indentations, which is the most stable solution and works even after the device is rebooted. However, if the interface looks “got”, try to change the aspect ratio in the same menu as well.

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Forced scaling in the developer menu is the most reliable method, guaranteeing 100% results on any version of MIUI.

Use of the “Full Screen Mode” function in settings

The more recent versions of the MIUI 12 and MIUI 13 shell, which are relevant to the Xiaomi Redmi 9, have a simpler option that does not require deep immersion in the engineering menus, which allows you to control the display of applications manually through the standard menu of screen settings.

Open Settings, go to Screen and find Full Screen Mode (sometimes called Application Size Management) and the list that opens will show all programs that the system considers to be unoptimized. Search the Phone app (a green handset icon) and activate the slider.

If activation is successful, try a test call, and the interface should cover the entire display area, hiding the cutout under the camera and using all available usable area, which is especially important for models with large diagonals, where the loss of space is more noticeable.

• 📱 Make sure that the list of applications shows the system call, and not third-party software like Viber or WhatsApp.
• 🔄 After changing the settings, it is recommended to completely close the phone application through the Task Manager and open it again.
• 🔍 If the slider is not pressed or immediately disconnected, then the system considers the application to be fully compatible and you need to use the method through the developer menu.

It is worth noting that in some regions (such as Russia or Europe), the menu may be called “Screen aspect ratio,” and the logic of the action remains the same: we search for the call app and force it to change from “Automatic” to “Full screen.”

Problems with the theme of design and their solution

As mentioned earlier, Xiaomi's visual style is heavily influenced by the themes set. If you like customizing the interface, chances are that's the reason for the small call window. XML-window markups, setting fixed dimensions that do not change system settings.

To diagnose a problem, temporarily switch to a standard theme "Classic" or "Default." Go to the Topic app, select a profile and click "Apply." After applying, check the incoming call. If the window is full, then the problem was in the third-party theme code.

You don't have to give up beautiful themes completely. You can try to find modifications in the theme store that are labeled "Optimized for Full Screen" or "MIUI 12/13 Compatible." Often, theme authors release revised versions that take into account the features of widescreens.

⚠️ Note: When removing the theme, all call settings (talk recordings, blacklist) are saved, but visual settings (caller wallpaper, fonts) may be reset.

There is also a method of manually editing a theme through the MIUI Theme Editor on PC, but it requires skills in working with resource files and is not recommended for ordinary users because of the risk of disrupting the stability of the system.

Resetting the settings of the “Phone” application

If the software settings don’t help, there may be errors in the cache of the Phone app that prevent you from correctly determining the screen resolution. Resetting to factory settings for a particular application is a safe procedure that won’t delete your contacts or call history.

To perform the reset, go to Settings → Apps → All Apps. Find Phone (Google system app or MIUI Dialer) in the list. Click on it, select Memory, and then clear → All Data.

Path: Settings → Applications → All apps → Phone → Memory → Clean → All data

After this operation, the phone can restart or simply reset the call settings. When it starts, the system will reanalyze the display settings and apply the current zoom rules, which often helps in cases where the problem occurred after the firmware update.

Comparison of problem-solving methods

To make it easier for you to choose the right way to fix the problem, we have prepared a summary table that will help you evaluate the effectiveness of each method depending on your situation and the version of the software.

As you can see from the table, the most versatile solution is to use the developer menu, which works on almost all versions of Android and MIUI. The rest of the methods should be used as ancillary or for initial diagnosis.

If neither of these methods worked, it may be a touchscreen hardware malfunction or a deep firmware failure, in which case a full Wipe Data reset with a pre-reserve backup is recommended, but this is an extreme measure.

Frequently Asked Questions (FAQ)

Customizing your smartphone’s interface is an important step towards a more comfortable experience. We hope our recommendations have helped you make a full-screen call on Xiaomi Redmi 9 and eliminate visual inconveniences. Remember that regularly updating your system and using proven themes will help you avoid similar problems in the future.