Depending on the Android device that you’re using, you may not have that much internal memory. Those of us with devices that can accommodate SD cards are somewhat lucky. However, apps can’t be stored to these SD cards by default. This is why mounting the SD card as an internal memory is desirable. By doing this, you can do things like store apps on your SD card to free up more space than is usually possible when using a regularly-formatted SD card.
Luckily, since Android Marshmallow, this is actually possible for the majority of Android devices out there without rooting.
Mounting an SD Card as Internal
In this case, a feature called “adoptable storage” is your friend. With this, you can use an SD card as if it is permanent internal storage. By doing this, the folders that are stored on your SD card are mounted as if they are internal ones. Subsequently, you are able to store data, including apps, on your SD card.
How to Enable Adopted Storage
In order to set up adoptable storage, you have to go to the storage settings of your device. This will vary from device to device. Open the Settings and find your way to the “Storage” section. Select “Storage Settings.”
You will then need to format your SD card. There will be an option that lets you use your SD card as internal storage. Select that one and let the formatting process run until completion.
Start Storing Stuff on Your SD Card
Head back to the storage section of your Settings app and select your SD card. You will notice that there is now more space available.
Next, you will need to select the “Migrate data” option.
Your device will give you details of how to free up some space.
Some Important Things to Note
When an SD card is formatted to be used as internal storage, it’s encrypted and can’t be used with another device. However, you can still remove the SD card and use other SD cards with your device.
You should also note that if you need to remove the SD card, that you should do this from within the storage settings on your device. Select your SD card and use the “Unmount” option.
You should also bear in mind that SD cards aren’t as fast as internal storage. This means you may experience a slight decrease in the performance of your device.
Reverting Your SD Card to a Portable Storage Device
If you ever want to resume using your SD card like a regular old portable storage device, you’ll have to format it again. To do this, select your SD card in the storage settings of your device and select the “Format as portable storage” option.
Caveat for Samsung Owners
By default, Samsung does not allow you to enable adoptable storage. However, you can root your device and install an adoptable storage enabler. Note that I have only tested this on a Samsung Galaxy Tab E running Android Nougat, however. Results may vary with newer devices.
If you are keen on freeing up some space on the internal storage of your Android device, then mounting an external folder as an internal one is a great option. You can mount the SD card as internal storage using Android’s adoptable storage option easily without rooting. You may be out of luck if you have a Samsung device, but it’s worth a shot anyway.