It's a Great Time to Go for a Drive
Storage has never been more plentiful or less expensive. For as little as $50, you can add a terabyte (TB) to your laptop or desktop via an external drive. That's enough to house hundreds of movie files or hundreds of thousands of MP3s or photos. Every computer you can buy, from huge desktop towers to budget-price Windows tablets, can connect to at least one hard drive, with no complex installation required. And if you're lucky enough to have multiple I/O ports, you can hook up many more. But which to choose? Here's everything you need to consider when shopping for an external hard drive.
Hard Drive Types
There are two types of external drives. Desktop-class drives, with 3.5-inch mechanisms inside, require a power adapter. They are designed to stay in one place, typically on your desk at home or at the office. If you're buying a desktop-class drive for video or lots of file transfers, look for one with a built-in fan, as the extra cooling will extend the drive's life expectancy. Notebook-class (aka pocket or portable) hard drives are usually 2.5-inch mechanisms powered through the connector cable. You can slip a 2.5-inch model into a coat and even some pants pockets.
Desktop-class models currently top out at 8TB per mechanism, but some drive manufacturers put two or more mechanisms into a chassis for more storage (for example, two 4TB drives for a total of 8TB of storage). Notebook-class drives come in capacities up to 4TB, but capacities from 500GB to 2TB are most common.
A word about multiple drives: You can increase capacity, speed, or data protection by buying an external RAID array, but multiple drives add expense and (some) complexity. Once you connect a single-volume external RAID array to your PC or Mac, it will show up and act as any other external drive. After that, it can become more complex. You should consider a drive with support for RAID levels 1, 5, or 10 if you're storing really important data that you can't afford to lose. There are other RAID levels for speed and capacity, and both software and hardware RAID implementations. Read our primer, RAID Levels Explained, for a more in-depth explanation.
Another type of external storage is the solid-state drive (or SSD), which uses a type of flash memory to store data rather than spinning platters. These drives are faster, and in most cases cost quite a bit more than external hard drives. Check out The Best SSDs for our recommendations. Want to know more about how hard drives and SSDs compare? Check out SSD vs. HDD: What's the Difference?
Input, Need Input
External drives connect to PCs and Macs via external cables. USB 2.0 and 3.0 ports are almost always present, though there are also newer connectors like USB-C. USB 3.0 provides fast transfer speeds (up to 5Gbps theoretical throughput) and a minimum of fuss, since it's backward-compatible and almost all desktop and laptop PCs come with USB ports. The newer USB-C standard is faster still (10Gbps, or twice the speed of USB 3.0) and supported using the smaller and more convenient USB-C connector, but right now it is still somewhat uncommon to find on drives.
You may find older external SATA (eSATA) or FireWire ports on some drives, though they can't reach the speeds that USB 3.0 or USB-C can. Thunderbolt and Thunderbolt 2 use the Mini DisplayPort connector and promise even faster speeds (up to 20Gbps), but have largely been supplanted by USB-C ports with Thunderbolt 3, which boast blazing throughput of 40Gbps (assuming your computer supports the technology). Although Thunderbolt, which was originally developed by Intel and championed by Apple, has been something of a niche player, the inclusion of only USB-C/Thunderbolt 3 ports on Apple's new MacBook Pro laptops could easily spur wider-spread adoption this year.
The external drives we've reviewed all have USB connectivity of one sort or another, but it's important to check that the drive you're considering is compatible with your computer. A handful of USB memory sticks and hard drives are currently available with both USB 3.0 and USB-C support via two separate connectors. Optional adapters will let you use older USB drives with PCs with newer USB-C ports.
How Important Is Drive Speed?
While a 7,200rpm drive is inherently faster than a 5,400rpm drive, the real answer would be "it depends." If you are transferring lots of files over a speedy interface like USB 3.0/USB-C or Thunderbolt, then by all means go for the 7,200rpm drive. But if you're limited to USB 2.0 or FireWire, then I would trade speed for capacity and get the largest 5,400rpm drive your budget allows. USB 2.0 and FireWire 800 are older interfaces that work fine with a 5,400rpm drive. If all-out speed is your goal, running multiple drives over Thunderbolt 3 is the fastest (and costliest) way, with a single SSD connected via Thunderbolt 1/2 or USB 3.0/3.1 as next fastest, and so on.
Do you care what your drive looks like? You can buy different colored drives for each family member, for example. Included software is a factor if you don't already have a local or online backup plan. If you're simply using the drive as an extra storage container, or if you're using the backup software built into Windows or macOS, the software bundled with the drive isn't as important. Warranty length is also a big factor in our ratings: Drives can and will fail. That cheap drive you found on a deal site may only come with a one-year warranty. Look for a three- or five-year warranty if you're hard on your drives.
To get you started toward the right add-on backup/storage solution, below are 10 of the best drives we've tested recently at a variety of prices and capacities. For more options, take a look at our lists of the best network-attached storage (NAS) devices and cloud storage services.
Featured External Hard Drive Reviews
CalDigit Tuff Review
%displayPrice% at %seller% Not only is the CalDigit Tuff a rugged hard drive designed to survive extreme conditions, it's also a terrific value. Read the full review
LaCie 5big Thunderbolt 2 Review
%displayPrice% at %seller% The LaCie 5big Thunderbolt 2 is a powerful external hard drive system capable of holding up to 40TB of data individually, and more than a petabyte when connected together. But it doesn't come cheap, and it lacks USB ports. Read the full review
Seagate Backup Plus Portable Drive Review
%displayPrice% at %seller% The Seagate Backup Plus Portable Drive gives you 4 terabytes of speedy storage you can take with you, as well as a personal cloud, all for a very reasonable price. Read the full review
Buffalo MiniStation Extreme NFC Review
%displayPrice% at %seller% The 1-terabyte Buffalo MiniStation Extreme NFC has a built-in cable you can't lose, a rugged chassis that will survive a rough daily commute, and an NFC card and reader add some security to this portable hard drive. Read the full review
CalDigit T4 RAID Review
%displayPrice% at %seller% Boasting throughput rates of higher than 500MBps and a 6TB formatted capacity, the CalDigit T4 RAID is a speedy, spacious drive that's well equipped for quickly tackling multitrack audio and 4K video projects. Read the full review
LaCie Porsche Design Mobile Drive Review
%displayPrice% at %seller% The 2TB LaCie Porsche Design Mobile Drive is a thin and super-fast portable hard drive that is not only attractive, but also USB-C compatible. Read the full review
Promise Pegasus2 R2+ Review
%displayPrice% at %seller% The 6TB Promise Pegasus2 R2+ is a versatile external drive for Thunderbolt 2-equipped Macs and PCs. It uses a two-drive RAID array for speed and capacity, but it can be supplemented with removable hard-drive pods or its included media card reader. Read the full review
Seagate Backup Plus Ultra Slim Review
%displayPrice% at %seller% The Seagate Backup Plus Ultra Slim is an external hard drive that provides 2TB of storage space, quick data transfer speeds, and a sharp, super-slim design for just $100. Read the full review
Seagate Innov8 Review
%displayPrice% at %seller% Aimed at power users and those with big media collections, the Seagate Innov8 is an external hard drive that packs 8TB of storage and connects via fast USB-C. Read the full review
Western Digital My Passport (2016, 4TB) Review
%displayPrice% at %seller% The 4TB Western Digital My Passport is a solid portable hard drive that combines capacity and value with funky design and good performance. Read the full review
G-Technology G-Drive ev ATC With Thunderbolt Review
%displayPrice% at %seller% The G-Technology G-Drive ev ATC is a rugged external hard drive with a removable enclosure that's made for traveling users who regularly find themselves at the mercy of the elements. Read the full review
Transcend Storejet 300 for Mac Review
%displayPrice% at %seller% The 2-terabyte Transcend Storejet 300 for Mac has both Thunderbolt and USB 3.0 interfaces, which can be convenient if all of your USB ports are occupied. But you'll pay for that flexibility. Read the full review