After 18 hours of new research and testing, we found that the 2 TB Seagate Backup Plus Slim is still the best portable hard drive for most people. It’s reliable, it’s one of the lightest, thinnest hard drives we tested, and it was faster than the competition in our backup and file-transfer tests.

The Slim has been one of our top picks for the past four years, and it’s the only portable hard drive that we’ve tested that doesn’t sacrifice size, speed, or reliability. Every other 2 TB portable hard drive is significantly larger, performs slower in our tests, or has a failure rate that’s too high to recommend. The Slim has an acceptable 9% reported failure rate among thousands of user reviews. We recommend the 2 TB model because it’s a great value. Seagate includes handy backup software, too.

If you want more storage and don’t mind a larger, heavier drive, we continue to recommend the 4 TB Seagate Backup Plus Portable, which costs less per terabyte than the 2 TB Backup Plus Slim. It was faster at sequential reading in our HD Tune test, but it was slower in our other testing. It’s twice as thick as our top pick and almost twice as heavy, too. (Make sure not to buy the 4 TB Seagate Backup Plus Fast by mistake – that’s a different drive that we do not recommend.)

Why you should trust us

Wirecutter has researched and recommended hard drives since early 2012, and our PC team has over eight years of combined experience testing hard drives and solid-state drives. I’ve spent the last two years reviewing hard drives and SSDs. We’ve collectively spent nearly 200 hours researching and testing portable hard drives in just the past four years.

Who this is for

If you’re not backing up the important documents and photos on your computer, you should start. Your computer’s internal drive will stop working someday, and unless your data is backed up, it’ll be gone forever. Fortunately, backing up your data is easy and getting started takes only a few minutes: Read our advice and set up a system that will back up your files automatically both to an external hard drive and the cloud. Just backing up to one or the other isn’t enough; having both onsite and cloud backups ensures that your data stays safe from localised threats such as fire, theft or natural disaster, as well as internet outages or disruptions to the cloud backup provider. A portable hard drive is a great local backup for a computer you take from your house to the coffee shop, on business trips or on vacations.

You should consider replacing your backup drives between the third and sixth year of use. If your drive dies and you have a cloud backup, you won’t lose data, but restoring from the cloud will take a very long time. According to statistics from cloud backup service Backblaze, hard drives are most likely to fail either within the first 18 months of use or after three years. About 5% of drives fail in the first 18 months of use, and the failure rate lowers to about 1.5% for another 18 months. At three years of service, the failure rate jumps to almost 12%. At the four year mark, the failure rate is 20%. Based on five years of data, Backblaze estimated that more than half of hard drives will last six years.

If you frequently move between different locations and need a drive to keep in your bag and use to back up photos and other data while you’re traveling, you should get a portable external drive like the ones we recommend in this guide. But if you spend most of your time working from one desk, a desktop external drive is the better choice. They’re less expensive per terabyte and a bit faster than portable drives, but desktop external hard drives are bigger and heavier than portable ones and require an additional power adapter. And although one bump can still lead to failure, portable hard drives are designed to withstand a little more abuse than desktop hard drives. If you can afford to pay around three times more for a smaller, lighter, more durable and much faster portable drive with hardware encryption, we recommend a portable solid-state drive.

How we picked

Ideally, a portable hard drive is something you don’t notice much. It should sit on your desk, quietly storing and backing up your data. And if you want to throw it in your bag (carefully), that shouldn’t be a problem. These are the features you should look for in a portable hard drive, in rough order of importance:

• Reliability: Although reliability is the most important factor for any storage device, solid information on reliability can be hard to come by. Only three companies still manufacture hard drives – Seagate, Western Digital, and Toshiba – and all of them make reliable hard drives. But all hard drives die. While the vast majority of drives from these manufacturers will be fine until you upgrade to a faster, more spacious drive in a few years, it’s still possible to buy a bad egg that will die too soon.
• Build quality: Your portable hard drive should be able to withstand normal wear and tear from being handled and thrown into your bag often. Rugged portable drives are bulkier and more expensive than the portable drives we recommend for most people.
• Physical size and weight: The smaller and lighter, the better. Your portable hard drive should also draw all the power it needs from the USB port, no power adapter necessary.
• Speed: Even though portable hard drives are generally slower than their desktop brethren, speed is still important. You’re more likely to use a portable drive to transfer large files between different computers, so a faster drive will save you time. We considered only those drives with USB 3.0 connections. Anything faster isn’t necessary for hard drives, because they’re limited by disk speed, not the USB interface.
• Price: We found that most people buy 2 TB and 4 TB drives by looking at Amazon reviews for our top picks. While a higher-capacity drive is more cost-effective per terabyte, 4 TB portable hard drives cost nearly twice as expensive as 2 TB drives and supply more storage than most people need. Since many portable drives nowadays have similar performance, lower-cost options are better.
• Capacity: We recommend getting the largest capacity you can afford right now because you’ll amass more data over time and larger drives generally have a better price-per-terabyte value. We focused on 2 TB drives because of their balance of value and total cost. We also have a 4 TB pick for people who need more portable storage and don’t mind the larger size.
• Warranty and customer service: A good warranty is important in case you get a lemon. While the majority of portable hard drives we tested have two-year warranties, a couple have three-year warranties. Responsive customer service is important, too, in case you have trouble backing up your data.
• Backup software: While backup software is a nice perk, you can find lots of free alternatives and other great options for online backup services. If you don’t need the extra features provided by the software, it’s not worth the time and effort to set it up on every computer you use. Dragging and dropping files works just fine for manual backups, and your OS’s built-in backup utility suffices for automatic ones.

How we tested

For our 2018 update, we narrowed down our list of contenders by price and capacity and tested six 2 TB models and one 4 TB model. For each portable hard drive, we ran HD Tune Pro, a benchmarking program that tests sequential transfer speeds and random access time across the entire disk. You can read a more in-depth explanation of the program at the HD Tune website. We also timed the file transfer of a 45.5 GB rip of a Blu-ray movie from start to finish, running each transfer three times and determining the average to rule out performance hiccups. Finally, we timed how long it took each external hard drive to back up 38.5 GB to Time Machine on a 2016 MacBook Pro.

To spot any widespread reliability issues, we read through Amazon reviews for each of the drives we tested and counted the number of reported drive failures. This method has shortcomings. For one, people are more likely to post a review when they have a problem. Also, because of the limited information available in some reviews, it can be hard to differentiate between hardware failures and software issues or user errors that could cause problems with a drive. But this approach is the best we have for now.

We also looked at Backblaze’s hard drive reliability ratings from 2017, which are based on more than 90,000 drives used in its cloud backup servers. Backup servers are a very different environment than a box on your desk – bare drives in servers are accessed more often and are subject to more vibrations and more heat; drives in enclosures have more potential points of failure between the USB connector and the USB-to-SATA logic board. The hard drives Backblaze uses are desktop hard drives, not portable hard drives, with some drives pulled from external enclosures. Even so, the Backblaze study is the largest, most recent sample of hard drive failures we have access to, and it’s always a fascinating read.

Our pick: 2 TB Seagate Backup Plus Slim

The 2 TB Seagate Backup Plus Slim is the best portable hard drive for most people because it’s reliable. It’s lighter and smaller than most of the other hard drives we tested, was consistently faster than most of the competition in our tests, and is one of the least expensive drives per terabyte we tested. The Slim also comes with handy backup software.

The Slim has been one of our picks since April 2014 because it continues to be the most reliable drive (based on the largest sample of Amazon reviews) while still providing fast performance. In May 2018, we recorded 249 failure reports out of 2,701 user reviews for the 2 TB model, giving the Slim a 9% reported failure rate – that’s pretty good for a drive that’s been around for four years, since drive failure rates start going up after three. During our years of testing, we’ve found that reported failure rates below 10 percent aren’t cause for concern.

Multiple Wirecutter staffers have been using the Seagate Backup Plus Slim for all kinds of things with few to no issues. Lead editor Kimber Streams has been using the drive “to store and transfer personal files, work photos, and test data for about four years”, and has “never used the included software or the app”, but notes that “the drive still works great”. Staff writer Thorin Klosowski has been using the drive with a PlayStation 4 for about a year to store games and data, “and it’s ticking along just fine, even though the PS4 has a knack for requiring a database rebuild if you don’t power it down right”. And senior staff writer Joel Santo Domingo has been using the drive for Time Machine backups and other data storage for two years. He writes, “it’s fast enough to use on a day-to-day basis, and in that time, I’ve yet to fill it up.”

The Seagate Backup Plus Slim is one of the thinnest and lightest portable hard drives we tested. It’s less than half an inch thick – 0.48 inches, to be exact – and it weighs just 5.6 ounces, making it easy to throw into a bag when you’re on the go. It’s 4.47 inches long and 2.99 inches wide. Most drives we tested were similarly speedy but were much thicker, which is why the Slim is our pick over anything else. The only 2 TB drive that’s lighter and thinner than the Slim is the Ultra Slim.

The Slim was roughly as fast as the competition at reading and writing Blu-ray video, and it was even faster in our Time Machine testing. It was firmly in the middle of the pack for our Blu-ray testing, reading and writing our files in 6 minutes and 33 seconds, and it measured as one of the fastest portable hard drives we tested with Time Machine, writing 38.5 GB to our MacBook Pro in 24 minutes and 9 seconds.

In HD Tune write testing, the Slim was the fastest portable hard drive we tested, measuring 86.4 MB/s, although its margin of victory fell within the margin of error of our measurements of other portable hard drives’ speeds. Its HD Tune read speed, 88.1 MB/s, was one of the fastest speeds we tested.

The Seagate Backup Plus Slim’s sturdy plastic case doesn’t flex or creak under pressure like many other drives do. It also stands up well to light scratches from keys – only the glossy black sides dinged up in our tests. Although our pick will hold up well to normal bag friction, it isn’t rated to survive any significant shocks.

We recommend the 2 TB Seagate Backup Plus Slim because it’s less expensive per terabyte than the 1 TB model and it’s the highest capacity option the Slim has. (If you need more space, consider the 4 TB Seagate Backup Plus Portable.) Even if you have only a terabyte of data right now, your needs will expand over the drive’s lifespan, and having room to grow is better than buying multiple drives and spending more in the long run. The Backup Plus Slim was on the cheaper end of the portable hard drives we tested; while the WD My Passport and WD Elements cost about the same, everything else cost at least $2.50 more per TB.

The user-friendly Seagate Dashboard interface lets you back up your PC, mobile devices, and social media, or it can restore from an existing backup. The Seagate Mobile Backup app for iOS and Android also backs up contacts, messages, photos, and other data from your smartphone to your hard drive via Wi-Fi or your phone’s data connection as long as the drive is plugged into a computer running the Dashboard software.

The Seagate Backup Plus Slim hasn’t been reviewed recently, but CNET and StorageReview both praised its performance and value when the drive was released in 2014. It has a 4.0-star rating on Amazon out of 18,884 reviews – a larger pool of reviews than any other portable hard drive we’ve tested.

Flaws but not dealbreakers

As PCSTATS notes, the Backup Plus Slim’s USB port wobbles up and down when pressure is applied to the cable more than with other drives. Always disconnect the cable before stashing the drive in a drawer or bag. The USB connection is the weakest point in the external drive, and if you break the port, you won’t be able to access your data until you find a new enclosure.

The Seagate Backup Plus Slim comes with a two-year warranty – Western Digital, Seagate’s biggest competitor, usually provides three-year warranties – and our perusal of Amazon reviews turned up more complaints about Seagate’s customer service than about WD’s. However, a two-year warranty should be sufficient, and several drives we’ve tested have only one-year warranties, so we don’t think this is a dealbreaker.

Seagate also sells two- and three-year data recovery plans, but we’ve seen several reviewers complain about long waits and a lack of communication from Seagate customer service. Instead, we recommend taking 15 minutes to set up an automatic backup that sends your files to an external drive and encrypted cloud storage without any regular action from you. Data recovery plans never guarantee success, and a thorough backup system is the only way to prevent data loss.

Our pick doesn’t have encryption to protect your data from prying eyes. While the option to encrypt would be nice, it isn’t a dealbreaker for most people. If you really need encryption, use an encryption utility like Veracrypt (or Bitlocker) or consider a portable solid-state drive.

More storage, less portability: 4 TB Seagate Backup Plus Portable

If you care more about price and storage space than size, you should get the 4 TB Seagate Backup Plus Portable. It costs almost the same per terabyte as the 2 TB Backup Plus Slim, and it was about as fast when reading and writing HD Tune transfer tests. The 4 TB model was slower in our other tests though, and it’s much thicker and heavier than the Slim. (But don’t buy the 4 TB Seagate Backup Plus Fast by mistake. We don’t recommend that drive, because with two 2 TB drives inside, it has higher potential to fail.)

Seagate sells a 5 TB model that’s the same dimensions and weight as the 4 TB version, and we found the larger capacity to be about 5% faster in our 2016 tests. It’s about the same price per terabyte right now, so you should buy it if you need the extra space in a portable drive. But if you want the fastest, most cost-effective drive and don’t care about portability, take a look at our desktop hard drive pick instead. It’s cheaper per terabyte and faster than the Backup Plus Portable, though it requires an AC adapter.

The 4 TB Seagate Backup Plus Portable was nearly as reliable as our top pick: We found a 10% failure rate out of nearly 1,500 Amazon reviews. The Backup Plus Portable was a little faster than the Backup Plus Slim in the HD Tune benchmark, achieving results of 101.1 MB/s read and 88.1 MB/s write – 13 MB/s and 1.7 MB/s faster, respectively, than the Slim. (Its write speed is not fast enough to separate it from the Slim, though.) The Portable performed respectably in our Blu-ray and Time Machine tests, but the Slim made better time. Both models are fast and reliable, and you should expect to see similar everyday performance from these drives.

The extra capacity comes with a minor downside: The Portable is larger and heavier than the Slim. Measuring 4.51 by 3.07 by 0.81 inches and weighing 8.6 ounces, the Portable is almost twice as thick and heavy as the Slim. Otherwise the Portable’s build quality is identical to the Slim’s, down to the slightly wobbly USB port.

The Backup Plus Portable comes with the exact same software as the Slim, and you can read our thoughts on that in the section above.

PCMag gave the Portable an Editors’ Choice award in January 2016, and AnandTech called it “one of the most cost-effective and easily portable storage media” in August 2015. The 2 TB and 4 TB Slim models share a review pool on Amazon.

What about wireless portable hard drives?

We don’t think wireless portable hard drives are useful for most people, but the WD My Passport Wireless Pro 2 TB is our pick for professional photographers on the move. The drive’s SD card slot (a feature other wireless hard drives lack) can automatically copy the contents of a memory card to its internal hard disk, and built-in Wi-Fi makes the images available to devices running iOS, Android, macOS, or Windows. It’s also available in a 3 TB capacity.