Some Android phones can format a microSD card as internal storage, also called adoptable storage. The card becomes encrypted and tied to that phone so apps and data can use it more like built-in storage.
This applies only to phones with a microSD slot that still support adoptable storage. Samsung disables this on many Galaxy models, current Motorola support is limited or absent, and Pixel phones do not have SD card slots.
Does This Affect You?
Use this if your phone storage is nearly full and your specific model offers Format as internal. If the option is missing, there is no normal setting that forces the feature on.
Format the SD Card as Internal Storage
- Insert the microSD card.
- Back up anything on the card. Formatting erases it permanently.
- Open Settings > Storage.
- Tap the SD card name.
- Open the menu or Storage settings.
- Tap Format as internal if available.
- Confirm the warning and choose whether to move data now.
After formatting, the phone encrypts the card and treats it as part of its own storage. The card will not work normally in another device unless formatted again.
Move Apps or Data to the Card
- Open Settings > Apps.
- Choose a large app.
- Tap Storage.
- If Change appears, tap it and select the SD card.
- Repeat for games, offline maps, streaming downloads, or other large apps that allow moving.
Not every app supports moving. If Change is missing, that app must stay on built-in storage.
Important Warnings
Use a Fast Card
Slow cards can make the entire phone feel sluggish when apps run from them. Use a reputable UHS-I U3 or faster card if you are buying one for this purpose.
Eject Before Removing
Removing adopted storage without ejecting can crash apps or destabilize the phone. Use Settings > Storage > Eject before taking the card out.
Reversing Erases the Card Again
To make the card portable later, open Storage settings and choose Format as portable. This erases the card and apps stored there must be reinstalled or moved first.
Sources
- Android Help Center: Adoptable storage overview
- Samsung Support: Format an SD card as phone storage
- Google Support: Free up space on Android