Taking storage with you may be less necessary than it once was, but there's still plenty of use cases where it's needed. There are various options out there including traditional hard disk drive (HDD) as well as much-faster solid-state drives (SSD). Here we review and rank the best ones.

Most portable USB drives are powered by the connected computer, so you can use them on the move without the need to plug into the mains or use batteries. Some will even connect your phone or tablet and let you extend storage that way, or allow you to transfer or open files.

Also see: Best Tech Deals

Capacity

Even in the smallest portable drives you’ll likely find are 128GB in size, which is enough to space thousands of CD albums in lossless FLAC format, or even more in lower quality MP3 or AAC formats. Off-loading your music collection alone from a computer to a portable drive can be a godsend in freeing valuable space if your laptop has limited storage.

Another popular application of portable storage is for keeping critical backups of your data held on a PC or laptop. You may be able to keep a perfect clone of your entire computer’s internal drive, on standby and ready in the event that the computer is lost or its drive should malfunction.

Alternatively, you may choose just to back up the most important files and documents from your user libraries, such as text documents, photos, films, music and stored email. Some portable drives include software that can help automate this process, keeping your selected directories in sync whenever you plug in the drive or by a daily schedule.

Performance

Now that USB 2.0 has been banished from all self-respecting storage, we find USB 3 as the standard for connection, letting these portable drives perform as quickly as the little disks inside will allow.

This means that when transferring your music or video collection to or from your PC to an HDD, you can expect around 100MB/s read speed (and typically the same for writing, since unlike flash storage technology the read and write speeds tend to be more symmetrical).

Compare this with the older drives using USB 2.0, which would limit speeds to around 35MB/s, or only one-third the speed. So in real terms, your 100GB of media files would take close to an hour to transfer with USB 2.0, or under 20 minutes using USB 3.0.

If you’re likely to be storing or backing up many small files, be aware that overall performance will plummet since hard disks tend to choke on smaller files. So while large files may zip across at 100MB/s, the smallest will likely travel at less than 1MB/s, or one hundredth that speed.

USB 3 is confusing, as USB 3.0 was retrospectively renamed to USB 3.1 Gen 1. There’s also a newer version, USB 3.1 Gen 2. This doubles the potential throughput from Gen 1’s 5Gb/s to 10Gb/s. In megabytes per second, these equate to 625 and 1,250 respectively. Pretty fast, then.

In reality, the fastest SSDs top out at around 550MB/s (although we have seen faster) and this speed is highly dependent on the device you’re connecting it to.

Check out the speeds in the summaries below, and go to the full review for more detailed speed-test results.

Protection

A rugged exterior will be handy if you want the freedom of being able to throw around the unplugged drive with less worry that it will damage the unit; and more importantly lose your data.

Look out for shock-resistance ratings such as the US military MIL-STD-810F 516.5 (Transit Drop Test). This means that it should withstand being dropped 26 times onto a hard floor, once on to each face, edge and corner, from a height of 1.22m.

Flash storage - more commonly known as SSDs - can survive more brutal treatment, and some portable drives are even water resistant. If you were to accidentally drop a portable SSD drive in water, then as long as the port covers are firmly closed, it will work fine to use it after it has been fully dried.

Some drives have an IP waterproof rating like phones.

Reliability

It’s tough to say definitively which manufacturer makes the most reliable hard drives. While there’s a big difference between the technology used in traditional hard drives and SSDs, both have a limited lifespan, and this is why warranties are relatively short - typically two or three years.

What’s important is that you have a well-thought-out backup process and you don’t rely on any single drive to store precious files. Ideally, you should have three copies: one on a PC or phone / tablet, one on a backup drive and one in the cloud.

Value

For many users, a portable storage drive may be an unavoidable commodity, and price will be the deciding factor. 

Often an older drive will be cheaper thanks to a drop in price so you might get a bargain, but make sure you're not missing out on new tech you'd benefit from.

Professionals will be willing to pay more for the faster and tougher SSDs out there.

Security

The larger the drive, the more you can store - and the more you stand to lose in the event of losing the drive or having it stolen. This is where it pays to lock down that drive.

There are two ways to ensure the data is unreadable by other users. You can scramble the contents through hardware encryption. Or you can use a software application to encrypt either parts or all of the drive.

Best portable hard drives & SSDs

1. Adata SD600Q

Adata SD600Q
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 21 June 2019

  • SSD, Average Read/Write speed: 417MB/s

It might forego the modern USB-C standard for connectivity but the Adata SD600Q is a great drive for anyone looking for a portable SSD and doesn't have a hugely demanding set of tasks for it.

The SD600Q provides a great combination of things including the robust and compact design, along with affordable prices for decent capacities - if you don't need more than 1TB.

It's also quick enough to copy files without having to wait for ages and you can also make use of Adata's free software if you like.

Read our Adata SD600Q review.

2. Seagate One Touch

Seagate One Touch
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 9 October 2019

  • SSD, Average Read/Write speed: 418MB/s

There's very little to dislike about the Seagate One Touch portable SSD. It offers an affordable, effective solution in a compact and robust form. What helps it stand out is the really useful Sync Plus tool that backs up files automatically.

Its Read/Write speeds will be acceptable for most users.

Really the only things missing are a longer cable and a USB-C port.

Read our Seagate One Touch review.

3. Caldigit Tuff nano SSD Drive

Caldigit Tuff nano SSD Drive
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 1 November 2019

  • SSD, Average Read/Write speed: 891MB/s

The CalDigit Tuff nano blew us away with its super-fast speeds, which are twice as fast as comparable portable SSDs. using NVMe technology, the 512GB drive we tested achieved Read and Write speeds close to 1,000MB/s!

It's also robust, being IP67 certified - meaning that it can be immersed in water and is dust-tight. It can also withstand drops up to 3M.

It is compatible with most computers (it comes with USB-C and USB-A cables), and, being USB-C, can also work with Apple's iPad Pro.

While it might be a little pricy for the casual user, professionals such as photographers and filmmakers will appreciate its blistering speed and tough travel credentials, and it's available in four colours (black, blue, red and green). We can't wait for the 1TB model.

Read our Caldigit Tuff nano SSD Drive review.

4. Samsung Portable SSD T5

Samsung Portable SSD T5
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 19 April 2018

  • SSD, Average Read/Write speed: 442MB/s

The T5 isn’t cheap, but it delivers on the critical performance that a portable SSDs are bought to ensure.

It's fast, with our tests showing it reached 440MB/s on Read and Write tests for larger files.

Using one with a laptop that has a hard drive is largely pointless, as the full speed advantages can only be achieved if used in combination with an internal SSD.

Read our Samsung Portable SSD T5 review.

5. G-Technology G-Drive Mobile

G-Technology G-Drive Mobile
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 29 January 2019

  • SSD, Average Read/Write speed: 543MB/s

It might not be the cheapest option but if you're looking for a portable SSD that's durable then the G-Drive Mobile is the way forward with its IP67 and casing you can drive over.

Performance is also very good (560MB/s Read and 520MB/s Write) so there's little to dislike here, only really the tiny cables supplied in the box.

Read our G-Technology G-Drive Mobile review.

6. Toshiba Canvio Advance Portable Hard Drive 4TB

Toshiba Canvio Advance Portable Hard Drive 4TB
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 2 November 2019

  • HDD, Average Read/Write speed: 146MB/s

The slim, lightweight 4TB Toshiba Canvio Advance offers a large capacity at a price well under what you’d pay for an SSD.

Yes, it’s slower than a solid-state drive but if you need a reliable backup drive this is an affordable option that is also faster than some of its competitors – scoring around 150MB/s in Read and Write tests.

It’s quite snazzy, too, in a range of glossy colours. It also comes in 1TB, 2TB and 3TB models, although we found availability patchy, and the 4TB is the best value.

Owners of USB-C computers will require a cable adapter.

Read our Toshiba Canvio Advance Portable Hard Drive 4TB review.

7. WD My Passport 4TB

WD My Passport 4TB
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 11 October 2016

  • HDD, Average Read/Write speed: 116MB/s

As a high-capacity portable hard drive, the WD My Passport 4TB (2016) offers cloud services, hardware encryption and has a respectable performance for an HDD.

At around 120MB/s, it clearly isn't as fast as an SSD, but the capacities can be far greater.

Read our WD My Passport 4TB review.

8. Transcend ESD400K

Transcend ESD400K
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 20 September 2016

  • SSD, Average Read/Write speed: 287MB/s

The Transcend ESD400K is a very light and portable SSD drive, with capacities from 128GB to 1TB with prices increasing as storage gets greater.

In our tests, its Read speed of 410.8MB/s is impressive, although its Write speed (163.8MB/s) much less so. We would recommend it for everyday use and as a means of efficiently backing up data.

At only 56g, the portable drive is easy to carry around and competes with some of the best portable drives in the market.

Read our Transcend ESD400K review.

9. SanDisk Extreme 500 Portable SSD

SanDisk Extreme 500 Portable SSD
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 31 August 2016

  • SSD, Average Read/Write speed: 300MB/s

For those that need high-speed portable storage, the Extreme 500 is a solid choice.

Read speed was very acceptable at 400MB/s, although the Write speed of 200MB/s is a little tardy compared to other SSDs reviewed here.

Capacities extend to 480GB which should be fine for most people. If you need more, look no further than the Samsung T5.

Read our SanDisk Extreme 500 Portable SSD review.

10. Toshiba Canvio Connect II

Toshiba Canvio Connect II
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 31 August 2016

  • HDD, Average Read/Write speed: 133MB/s

It’s nowhere near as quick as an SSD, but we saw 131MB/s when reading large files and 135MB/s when writing them in CrystalDiskMark’s sequential tests. This is reasonably good for a 5,400rpm hard drive. 

Aside from speed, the Toshiba Canvio Connect II is a brilliant all-round package. It offers acres of space for your backups and media library, it’s cheap and it comes bundled with genuinely useful software.

Read our Toshiba Canvio Connect II review.