Direct answer
Download the file to your phone, allow the app that opens it (Files or Chrome) to install unknown apps, open the APK, read the install screen, tap Install, then switch the permission off again.
Before you begin
- Back up your phone.
- Keep Google Play Protect switched on.
- Know where the file came from — the source matters more than the steps.
Step-by-step
- Download the APK, or copy it to the phone with a USB cable.
- Open Settings → Apps → Special app access → Install unknown apps.
- Choose the app you will open the file with and enable "Allow from this source".
- Open the APK from Files → Downloads.
- Read the screen: if it says it will update an app from a different developer, stop.
- Tap Install and wait.
- Turn "Allow from this source" off again.
Split APKs (.xapk, .apks)
Some apps are delivered as bundles of several APKs. Android cannot open these directly; they need a dedicated installer such as SAI (Split APKs Installer). Only use installers from trusted sources.
Updating and removing
To update, install a newer version signed by the same developer — the app data is kept. To remove, go to Settings → Apps → the app → Uninstall.
FAQ
Do I need root?
No. Installing APKs works on any normal Android phone.
Will it void my warranty?
No, installing apps does not affect the warranty.