Backing up the old SD card data If you're upgrading from an older 3DS (or just moving to a bigger SD card), you're going to need to back up the data from your old SD card.

You can format an SD card using Windows, Mac, and Android devices, and likely your digital camera too.

SD cards are enormously useful devices that hold more data every year. Reformatting an SD or microSD card can make sure all the data that was on it is gone.