Android 11 (API level 30) further enhances the platform, giving better protection to app and user data on external storage. This release introduces several enhancements, such as raw file path access, batch edit operations for media, and an updated UI for the Storage Access Framework.
The release also offers improvements to scoped storage, which makes it easier for developers to fulfill their storage use cases after they migrate to using this storage model.
Scoped storage enforcement
Apps that run on Android 11 but target Android 10
(API level 29) can still request the
requestLegacyExternalStorage
attribute. This flag allows apps to temporarily opt out of the
changes associated
with scoped storage, such as granting access to different directories and
different types of media files. After you update your app to target
Android 11, the system ignores the requestLegacyExternalStorage
flag.
Maintain compatibility with Android 10
If your app opts out of scoped storage when running on Android 10 devices, it's
recommended that you continue to set requestLegacyExternalStorage
to true
in
your app's manifest file. That way, your app can continue to behave as expected
on devices that run Android 10.
Migrate data to directories that are visible when using scoped storage
If your app uses the legacy storage model and previously targeted Android 10 or lower, you might be storing data in a directory that your app cannot access when the scoped storage model is enabled. Before you target Android 11, migrate data to a directory that's compatible with scoped storage.
Test scoped storage
To enable scoped storage in your app, regardless of your app's target SDK version and manifest flag values, enable the following app compatibility flags:
DEFAULT_SCOPED_STORAGE
(enabled for all apps by default)FORCE_ENABLE_SCOPED_STORAGE
(disabled for all apps by default)
To disable scoped storage and use the legacy storage model instead, unset both flags.
Manage device storage
Starting in Android 11, apps that use the scoped storage model can access only their own app-specific cache files. If your app needs to manage device storage, follow the instructions on how to query free space.
- Check for free space by invoking the
ACTION_MANAGE_STORAGE
intent action. If there isn't enough free space on the device, prompt the user to give your app consent to clear all caches. To do so, invoke the
ACTION_CLEAR_APP_CACHE
intent action.
App-specific directory on external storage
Starting in Android 11, apps cannot create their own
app-specific directory on external storage. To
access the directory that the system provides for your app, call
getExternalFilesDirs()
.
Media file access
To make it easier to access media while retaining user privacy, Android 11 adds the following capabilities.
Perform batch operations
For consistency across devices and added user convenience, Android 11 adds several methods that make it easier to manage groups of media files.
Access files using direct file paths and native libraries
To help your app work more smoothly with third-party media libraries,
Android 11 allows you to use APIs other than the
MediaStore
API to access
media files from shared storage using direct file
paths. These APIs
include the following:
- The
File
API. - Native libraries, such as
fopen()
.
Access to data from other apps
To protect user privacy, on devices that run Android 11 or higher, the system further restricts your app's access to other apps' private directories.
Access to data directories on internal storage
Android 9 (API level 28) started to restrict which apps could make the files in their data directories on internal storage world-accessible to other apps. Apps that target Android 9 or higher cannot make the files in their data directories world-accessible.
Android 11 expands upon this restriction. If your app targets Android 11, it cannot access the files in any other app's data directory, even if the other app targets Android 8.1 (API level 27) or lower and has made the files in its data directory world-readable.
Access to app-specific directories on external storage
On Android 11, apps can no longer access files in any other app's dedicated, app-specific directory within external storage.
Document access restrictions
To give developers time for testing, the following changes related to the Storage Access Framework (SAF) take effect only if your app targets Android 11 or higher.
Access to directories
You can no longer use the
ACTION_OPEN_DOCUMENT_TREE
intent action to request access to the following directories:
- The root directory of the internal storage volume.
- The root directory of each SD card volume that the device manufacturer considers to be reliable, regardless of whether the card is emulated or removable. A reliable volume is one that an app can successfully access most of the time.
- The
Download
directory.
Access to files
You can no longer use the
ACTION_OPEN_DOCUMENT_TREE
or the
ACTION_OPEN_DOCUMENT
intent action to request that the user select individual files from the
following directories:
- The
Android/data/
directory and all subdirectories. - The
Android/obb/
directory and all subdirectories.
Test the change
To test this behavior change, do the following:
- Invoke an intent with the
ACTION_OPEN_DOCUMENT
action. Check that theAndroid/data/
andAndroid/obb/
directories both don't appear. - Do one of the following:
- Enable the
RESTRICT_STORAGE_ACCESS_FRAMEWORK
app compatibility flag. - Target Android 11 or higher.
- Enable the
- Invoke an intent with the
ACTION_OPEN_DOCUMENT_TREE
action. Check that theDownload
directory appears and the action button associated with the directory is grayed out.
Permissions
Android 11 introduces the following changes related to storage permissions.
Target any version
The following changes take effect in Android 11, regardless of your app's target SDK version:
- The Storage runtime permission is renamed to Files & Media.
If your app hasn't opted out of scoped storage and requests the
READ_EXTERNAL_STORAGE
permission, users see a different dialog compared to Android 10. The dialog indicates that your app is requesting access to photos and media, as shown in Figure 1.Users can see which apps have the
READ_EXTERNAL_STORAGE
permission in system settings. On the Settings > Privacy > Permission manager > Files and media page, each app that has the permission is listed under Allowed for all files. If your app targets Android 11, keep in mind that this access to "all files" is read-only. To read and write to all files in shared storage using this app, you need to have the all files access permission.
Target Android 11
If your app targets Android 11, both the
WRITE_EXTERNAL_STORAGE
permission and the WRITE_MEDIA_STORAGE
privileged
permission no longer provide any additional access.
Keep in mind that, on devices that run Android 10 (API level 29) or higher, your
app can contribute to well-defined media collections such as
MediaStore.Downloads
without requesting any storage-related permissions. Learn
more about how to request only the necessary
permissions when
working with media files in your app.
All files access
The majority of apps that require shared storage access can follow the best practices for sharing media files and sharing non-media files. However, some apps have a core use case that requires broad access of files on a device, but cannot do so efficiently using the privacy-friendly storage best practices. Android provides a special app access called All files access for these situations. To learn more, see the guide on how to manage all files on a storage device.
Additional resources
For more information about changes to storage in Android 11, view the following materials: