Where file associations are stored in Android and how to configure them

When you try to open a document, picture or video on Android, the system automatically suggests a default application - or asks which one to use. This logic works thanks to file associationsthat associate extensions (for example, .pdf, .mp4) with specific apps. But what if Android opens files with the wrong application? Or if the desired app does not appear in the list at all?

In this article we will look at where are file associations physically stored in Androidhow to change them through standard settings, and also consider advanced methods using ADB system files. We will pay special attention to problems that arise after resetting the settings or updating the OS, when the bindings are reset to factory settings.

It is important to understand: the association mechanism depends on the version of Android. Starting from Android 10Google has tightened controls over default apps, and in Android 13+ added additional security restrictions. We will take into account all the nuances so that the instructions work on modern devices.

What are file associations and why change them

A file association is a rule by which Android determines which application should open a file with a specific extension. For example:

• 📄 .docx → Microsoft Word or Google Docs
• 🎵 .mp3 → Google Play Music or VLC
• 📹 .mkv → MX Player or Kodi

By default, Android prompts you to select an application when you first open a file and remembers the choice. However, sometimes this mechanism breaks down:

• 🔄 After updating the OS, all associations are reset.
• 🚫 The application has been deleted, but the association remains (files cannot be opened).
• 🔒 A virus or malware has replaced the default applications.
• 📱 The smartphone manufacturer (Samsung, Xiaomi, Huawei) blocks changing some associations.

Changing associations allows you to:

• 🛠️ Restore the functionality of files after a failure.
• 🔄 Regain control over opening files (for example, replace the standard player on VLC).
• 🔒 Block unwanted applications that arbitrarily assign themselves as default.

Where file associations are stored in Android: system paths

File associations in Android are stored in several places, depending on the type of binding:

All these files are in a protected area /data, and editing them requires root access or access through ADB with debugging commands. Without them, you can only change associations through standard Android settings (more on them in the next section).

Important: starting with Android 11, Google has prohibited direct modification of files in /data without root, even through ADB. This is done for security, but complicates manual configuration.

⚠️ Warning: editing system files without root can lead to data loss or cyclic reboot devices. If you are not sure of your actions, use only official methods (Android settings).

How to change file associations through Android settings

The safest way to change default applications is to use standard settings. The instructions are suitable for all versions of Android (from 6.0 to 14+), but the path may differ slightly depending on the shell (MIUI, One UI, ColorOS etc.).

Open Settings → Applications|Select Default applications or Application settings|Find the section Opening supported links or Set as default|Select the file type (for example, Audio, Video, PDF)|Specify the desired application from the list-->

If the required application is not in the list, follow these steps:

1. Install the application from Google Play (for example, FX File Explorer for working with files).
2. Open any file of the appropriate type manually (via a file manager).
3. In the window that appears, select the desired application and check the box Always (or Use as default).

On some devices (for example, Samsung Galaxy s One UI) the path may look like this:

Settings → Applications → Three dots (⋮) → Default applications → Set as default

⚠️ Attention: manufacturers often block changing associations for system applications (for example Galaxy Store or Mi VideoIn this case, only ADB or root will help.

Advanced methods: changing associations via ADB

If the standard settings do not help (for example, the application does not appear in the list or the system ignores your choice), you can use ADB (Android Debug Bridge). This method works without root, but requires the computer to be turned on. USB debugging and computer.

First connect the phone to the PC and run the command to reset everything associations:

adb shell cmd package reset-preferred-packages

If you need to reset associations for a specific application (for example, Chrome), use:

adb shell pm clear com.android.chrome

To force the default application for a specific file type (for example, .mp3 → VLC):

adb shell cmd package set-home-activity com.android.vlc/org.videolan.vlc.gui.video.VideoPlayerActivity

Full list of commands for working with associations:

Example: to force Google Photos to open all images, run:

adb shell cmd package add-preferred-activity com.google.android.apps.photos

Manual editing of system files (for root only)

If you have root access, you can manually edit association files. To do this:

1. Install a file manager with root support (for example, Root Explorer or FX File Explorer).
2. Go to /data/system/users/0/ and find files:
   • package-restrictions.xml —package restrictions.
   • mime_types.xml —MIME type bindings for applications.

<package name="com.example.app">
<activity name="com.example.app.MainActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="audio/mp3" />
</intent-filter>
</activity>
</package>

After editing, check that the files have the correct permissions:

chmod 644 /data/system/users/0/package-restrictions.xml
chmod 644 /data/system/users/0/mime_types.xml

⚠️ Attention: incorrect editing of XML files can lead to system crash or data loss. be sure to create a backup copy through TWRP or Custom Recovery.

Problems with file associations and their solutions

Even after changing the settings, problems may occur. Let's look at typical cases and ways to solve them:

If the problem is related to a specific manufacturer, try the following solutions:

• 📱 Samsung: disable Knox in the settings security or use ADB to bypass restrictions.
• 📱 Xiaomi: enable Developer mode and disable MIUI Optimization in the settings.
• 📱 Huawei: some associations are blocked at the firmware level - only flashing will help.

How to prevent file associations from being reset

To avoid losing association settings, follow these recommendations:

• 🔄 Back up your files regularly package-restrictions.xml and mime_types.xml (if there is root).
• 📥 Before updating the OS, reset associations via ADBto avoid conflicts:

  adb shell cmd package reset-preferred-packages

• 🛡️ Install an antivirus (for example, Malwarebytes) to protect against software that changes associations.
• 📱 Avoid using "optimizers" and "cleaners" (for example, Clean Master), which often reset settings.

If you often work with files of different types, consider using file managers with their own associations, for example:

• 📁 Solid Explorer — allows you to assign applications to open directly in the interface.
• 📁 FX File Explorer —supports manual management of MIME types.
• 📁 Total Commander —has a built-in editor associations.

For corporate devices (for example, managed Android Enterprise), association settings can be controlled by the administrator via Device Policy Controller. In this case, they can only be changed through the MDM console.

FAQ: answers to frequently asked questions

adb shell cmd package reset-preferred-packages