Some devices may support USB OTG, but for some reason don’t support mounting a USB drive (usually devices running an older version of Android). The Root Method: For Devices That Won’t Mount USB Drives

If you want to adjust more options, you can tap the menu button in the file manager while browsing the contents of the USB drive and tap “Settings.” There’s an option to “Format” the drive here, allowing you to erase its contents without taking it to a computer. If you have videos, music, or movies on the drive, you can tap them to open them in the media viewer applications on your device. This would allow you to watch videos stored on a USB flash drive on your phone while travelling, for example. Just long-press one or more files or folders to select them. You can browse and manage the files like you normally could. Tap the “Explore” button and Android’s new file manager will open, displaying the contents of the drive. RELATED: How to Use Android 6.0’s Built-in File Manager If you’re running an older version of Android, you may need the root-only StickMount app to access the files instead. You’ll see an “Explore” button that will allow you to browse the files on the drive, and an “Eject” button that will allow you to safely remove the drive. On modern versions of Android, you’ll get a notification saying the drive is “for transferring photos and media” after you attach it. The Non-Root Method: For Most Newer Devices

Formatting the drive will erase its contents, however, so you should ideally make sure it’s in the correct format when you first transfer files to it. If your device isn’t formatted with an appropriate file system, you’ll be able to format it after connecting it to your Android device.

Y Disk Flash Drive Instructions