How to make a theme for Xiaomi phone: from idea to MTZ

Personalization is the first thing that an advanced user looks for after buying a new smartphone. Standard wallpaper and icons quickly become boring, and the functionality of the system wants to expand. Owners of devices with MIUI shells and the new HyperOS have a unique advantage: they can not just download the finished design, but also create it themselves from scratch.

The process of creating custom themes seems complicated only at first glance. In fact, the file structure is logical, and the developer tools allow you to visualize changes in real time. You don't have to be a professional programmer to change fonts, notification sounds or redraw app icons.

In this guide, we’ll take you all the way from the workplace to the final compilation of the.mtz file, learn what tools the community uses, how to structure resources properly, and how to avoid the typical errors that may cause the system to refuse to install your project.

Necessary tools and environment preparation

Before you start drawing icons, you have to prepare software. The main tool is the official utility. MIUI Theme Editor. It allows you to import basic templates, edit. XML-Configuration and Predict Results on a Virtual Device.

However, professionals rarely rely on just one tool. Graphics will require layering and transparency-enabled graphics editors, such as Adobe Photoshop or free GIMP. XML and JSON code editing is best done with specialized text editors like Notepad++ or Visual Studio Code.

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Use the portable version of Theme Editor on a flash drive to access the project from any computer without re-installing dependencies.

It's important to decide on the concept beforehand. Will it be a minimalist Material Design theme or a Cyberpunk-infused theme? It's a choice of color deck and the set of graphic elements you need. Also make sure you have the source files of your model's stock theme to compare the sizes of the icons.

• 🎨 MIUI Theme Editor – The main development and compilation environment.
• ✏️ Graphic editor – for drawing icons and widgets (Photoshop, Figma).
• 💻 Text editor - for editing XML-configuration.
• 📱 Test device – Xiaomi smartphone for live checking the theme.

⚠️ Attention: Download MIUI Theme Editor only from official resources or trusted developer forums. Third-party builds may contain malicious code or work incorrectly with new versions of HyperOS.

Project structure and the theme file system

Any theme for Xiaomi is a rebranded one. ZIP-An archive with a certain internal structure, and understanding how folders are organized is critical to successful development, so if you put an image file in the wrong directory, the system will simply ignore it or display a standard element.

At the root of the project is always a file. description.xml. This is your theme passport, containing metadata: title, author, version, minimum version. MIUI and links to previews. XML-Theme Editor will not be able to assemble the project into an installation file.

The main resources are distributed by folder. Status bar images, app icons, sounds and fonts have their own reserved directories. For example, all icons are usually in the icons folder, and the lock screen configuration is stored in the lockscreen.

When working with file paths, always use relative links. Absolute paths from your computer (C:/Users/...) in the theme code will not work. Also remember that the theme file system is sensitive to the character register: Icon.png and icon.png are two different files.

Design development: icons and system graphics

The biggest part of the job is rendering icons, you have to create a single style for hundreds of applications, and MIUI uses a standard grid, but the sizes of the icons themselves can vary depending on the device model and the shell version.

Start by creating a substrate template. This will help you keep the same size and indentations for all icons. Use vector graphics where possible so that zooming doesn't lead to "ladders" at the edges. For raster graphics, always work in resolution, multiples of Retina screens and higher.

Remember the icon states. Some system applications have multiple statuses (e.g., battery charged/discharged, notification/no) All of these variations should be rendered and spelled out in the appropriate XML-manifestos inside the subject folder.

• 📐 Follow the grid – all elements should be centered.
• 🎨 Uniform style – use the same palette and line thickness.
• 🔍 Contrast – check the readability of the icons on different backgrounds.
• ⚖️ Optimization - compress PNG without loss of quality, reducing the weight of the topic.

⚠️ Warning: Avoid using too small details in icons. On a high-pixel density smartphone screen, they can merge into porridge, making the interface unreadable.

System graphics include volume sliders, curtain switches, battery indicators, and notification icons, which often go unnoticed, but they create a holistic impression of the theme. The color of the accents in the system settings should harmonize with your design.

Setting up the lock screen and clock widgets

The Lock Screen is the face of your theme, and users see it most often, so you can get the most creative out of it. Modern versions of MIUI use an engine that allows you to create complex animations and interactive elements.

To edit the lock screen, a special editor inside Theme Studio or manual editing is used. XML-You can customize the behavior of the clock, the calendar, the pedometer, and the shortcuts to quick access. It's important to consider that complex animations can consume more battery power.

The widgets on the desktop require special attention. They must be read as native by the system. This requires strictly following the structure of the clock and date tags in the configuration files. A syntax error will result in the widget simply not showing up or showing zeros.

When creating a custom lock screen, check the work of unlocking for fingerprint and facial recognition. Graphic elements should not overlap the areas of scanning biometrics, otherwise the functionality of the smartphone will be disrupted.

Sound design and tactile impact

The theme is not just visual, it's also sound. Replacing Xiaomi's standard tunes with original ones allows you to create a unique audio branding, you can replace the screen lock, SMS notifications, incoming calls, and even the charging sound of the device.

When selecting audio files, observe the duration restrictions. Short system sounds (clicks, focus) should not be longer than 1-2 seconds, otherwise they will be “chewed” by the system when used quickly. The file format should be compatible with Android, usually MP3 or OGG with a bitrate of up to 128 kbit / s.

Newer versions of HyperOS also offer the ability to customize tactile responses (vibrofeedback) when interacting with theme elements. Although it is an advanced feature that requires deep knowledge of the system, adding vibration patterns makes the use of the theme more tangible and enjoyable.

Remember to balance volume: System sounds should not be quieter or louder than standard messenger notifications, so as not to create an imbalance in the overall sound picture of the smartphone.

Compilation, testing and installation of the theme

After all the edits are completed, the compilation stage begins. MIUI Theme Editor press the Build or Compile button. The program will pack all your resources, check the integrity of the software. XML-file and create a final file with the.mtz extension.

There are two ways to set up a theme. One is through the file manager: open the.mtz file and select "Apply." The second, more reliable for the developer, is through debugging mode. USB and ADB-commands, or through a special application “Theme Editor” on the smartphone itself, which allows you to download themes from your computer over Wi-Fi.

adb push my_custom_theme.mtz /sdcard/MIUI/theme_cache/


adb shell am start -n com.miui.themes/com.miui.themes.ui.MainActivity

Testing should be done on a clean system or on a device that has pre-reset theme settings. Check all screens, settings menus, notification curtains and third-party apps. Pay special attention to dark topics — if you have implemented them, because in dark mode colors can invert unpredictably.

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A high-quality theme should weigh no more than 20-30 MB. Bloated graphic resources slow down the interface and can cause the Themes system process to crash.

⚠️ Note: When installing a theme from an unknown source (not through an official store), the system may issue a security alert.This is a standard Android reaction to installing apps/themes outside the GetApps store.

Frequent mistakes and ways to solve them

Even experienced developers face problems, and one of the most common is a black screen after applying a theme. XML-configuration made a syntax error or no critical system file found that the theme is trying to replace.

Another problem is interface layering. Items can go if you used pixel sizes without considering different screen densities (DPIs). Always use relative values or provide resources for different resolutions (hdpi, xhdpi, xxhdpi).

If the theme is not validated in Theme Editor, carefully examine the error log (Log).The program will specify a string in XML where the structure is broken. Often the problem lies in an unclosed tag or an extra character at the end of the line.

• 🚫 Syntactic errors in XML break down the topic load.
• 📉 Low productivity due to heavy PNG-picture.
• 🔲 Incorrect display on screens with a cutout (notch).
• 🔒 Blocking the download in the absence of a developer signature (for publication in the store).

To correct errors, use the exclusion method: return the original theme files one by one until the problem disappears, so you can figure out the culprit for the failure, and back up the working version of the project regularly before making major changes.

Questions and Answers (FAQ)