Starting with Android 8.0 Oreo, Google has significantly changed the way apps are installed from sources other than Google Play. The familiar global “Unknown sources” switch has been removed and replaced with a more granular permissions system. Instead of allowing all apps to install APK files, Android now requires you to grant this permission individually to each app. While this change initially confused many users, it has significantly improved overall security.
When attempting to install an app from sources other than Google Play, you may see a warning that installation from unknown sources is blocked for security reasons. This message is part of Android’s built-in security system and is not an error in the traditional sense.
How Permission to Install Apps from External Sources Works
Permission to install unknown apps is designed to protect your device from malware that may be hidden in APK files. Without explicit user permission, Android does not allow apps to install software from external sources.
On devices running Android 8.0 and later, there is a special settings section in the system that lists all applications that can act as installation sources. Each such application must be approved separately. For example, if you want to install an APK file using a file manager, that particular file manager must first be granted permission.
Allowing Installation from Unknown Sources on Android
Because Android looks different depending on the manufacturer’s firmware and interface, the names and locations of settings may vary slightly. However, the logic remains the same across devices.
To allow installation from external sources, you need to open the system settings and navigate to the privacy or security section. From there, open the special permissions area and find the option related to installing unknown apps. You will see a list of apps that can act as installation sources, such as browsers or file managers. Once you select the app you plan to use, you can enable permission to install apps from that source.
After confirming that you understand the potential risks, the system will allow APK installation through the selected app. If installation still fails afterward, the most common cause is insufficient free storage on the device.
To simplify permission management, Android also allows you to grant permission to install when attempting to install an APK file, for example from a downloaded file folder. When you start installing an app from an external source, a window appears warning you that the installation is blocked. You can immediately allow the app to be installed and continue with the installation.
