Best External Hard DrivesBest Overall: ​​ Best Portable: ​​ Best Ultra-Portable: ​​ Best Pocket-Size: ​​ Most Rugged: ​External hard drives are also an excellent insurance policy if something terrible happens to your computer. After not one but many unfortunate losses, I finally learned how important it is to own an external hard drive. At less than 4 inches long, this external hard drive feels more like a keyring than a hard drive capable of holding vast amounts of data. If you plan to haul your external hard drive around in a backpack or bag when traveling or commuting, then a portable hard drive is the way to go. : Because many computers these days come with large internal hard drives, it’s easy to overlook the need for an external hard drive.