The Best External Hard Drives of 2024

What to Look For in an External Hard Drive

Digital storage is changing. Internal storage drives are getting bigger, cloud storage is getting cheaper, and USB drives are getting less common. But that doesn't necessarily negate the need for an excellent external hard drive — sometimes, they're the best way to go.

Buying a hard drive is more complex than purchasing the first (or cheapest) one you see. There are several factors to consider when purchasing an external storage drive.

For starters, you'll want to decide between a hard drive and a solid-state drive, offering significant advantages and disadvantages. You'll also want to consider drive speed, hard drive format, connectivity, and exceptional protection features.

Before diving into our guide, you should know a few terms. You'll most likely decide between a drive of multiple gigabytes (GB) or multiple terabytes (TB). One terabyte is 1,000 gigabytes, and one gigabyte is 1,000 megabytes (MB). An MP3 file takes around 3.5MB, meaning one gigabyte can store about 285 songs. One HD movie takes up around 3.5GB — so one terabyte can hold 285 HD movies.

Here's everything to consider when buying an external drive.

Storage Size

The most important thing to consider is the size of your drive. We’re not talking about how physically big, but rather, how much storage you want. It’s hard to recommend a storage size because it varies from person to person and largely depends on what you plan on storing. However, a good rule of thumb is determining how much storage you think you’ll need and then buying a double drive.

If you plan on storing documents only, you probably don’t need much more than 80GB. If you’re storing a small to medium music collection and photos, then up to 256GB should be acceptable. The amount you need for storing movies and other video content could range into multiple terabytes, especially if the movies are in 4K. Ultimately, getting more storage than you think you’ll need is always good — even if it means shelling out more money.

Types of External Drives

There are two main types of external storage drives, and while they ultimately serve the same purpose, the way they store files is markedly different.

Hard Drive (HDD)

Traditionally, if you wanted a storage drive, it meant buying a hard disk drive. There are some advantages and some disadvantages to this. For starters, hard disk drives have been around for quite some time, so they've become relatively cheap. They store files on an electromagnetic disk that spins around and is read by a moving arm.

Because of those moving parts, they're much more likely to break with a lot of movement. The speed of a hard disk drive is dictated by how fast the electromagnetic disk spins, and they're generally slower than solid-state drives. (We'll get more into the different speeds later.) Hard disk drives are the way to go; however, if you want a lot of storage at a low price and don't plan on moving them a lot.

Solid-State Drive (SSD)

Solid-state drives do away with the moving electromagnetic disk and replace it with flash storage. That’s the same kind of storage used in smartphones, RAM in computers, and, these days, many of the internal storage drives in computers.

Solid-state storage uses microchips to store information, so no moving parts exist. That means a lower failure rate, higher speed, and better overall performance. In particular, they’re great for running software or an operating system.

Of course, price is a downside to all of those advantages. Solid-state drives are much more expensive than hard disk drives, and while they are going down in price, you can’t get multi-terabyte solid-state drives without spending at least a few hundred dollars.

Transfer Speed

The transfer speed of a hard drive depends on the type of connector the hard drive comes with. Newer connection standards have higher transfer speeds. The term “transfer speed” is technically a little misleading, as it doesn’t dictate precisely how fast a hard drive can transfer files to and from your computer.

Instead, it tells you how fast a hard drive can theoretically transfer files based on the connection protocol the hard drive uses.

In the past, the connector was the main limiting factor in how fast a drive could transfer files: USB 2.0 hard drives, in the real world, could transfer data at up to 20 MB/second, while FireWire 800 drives limited things to 85 MB/second.

These days, the newer USB 3.0 standard allows for data transfer at up to 460 MB/second, while Thunderbolt has speeds of over 1GB/second. Because of that, the connection type isn’t the bottleneck. Instead, the speed is dictated by how fast the hard drive can read and write data, referred to as the read/write speed.

Read/Write Speed

Read/write speeds refer to how quickly a hard drive can access the files stored within it — not how fast they transfer to or from a computer. The "read" speed refers to how quickly a hard drive can access a stored file, while the "write" speed refers to how quickly a drive can save a new file.

Given the development in transfer protocols, read/write speeds are a much better indicator of how fast your hard drive will be able to transfer files than "transfer speed," especially when it comes to hard disk drives.

Read/write speeds change a lot depending on whether it's an HDD or SDD; even within those categories, there can be some variation. As mentioned, HDDs have a spinning disk inside of them, and the rate at which drives can access data depends on how quickly that disk spins. Commonly, drives spin at 5,400RPM, or rotations per minute, and drives at that speed generally have a read/write speed of around 100MB/s. Some HDDs have a physical speed of 7,200 RPM, which allows for a slightly faster read/write speed of 120MB/s.

Read/write speeds can vary a lot with SSDs, but typically, they range from 200MB/s at the slowest to multiple GB per second at the fastest. If all you're doing is transferring files, then any of those speeds should be more than enough, but if you're using your drive to store software or your operating system, something on the fast end might help. In that case, look for speeds of 500MB/s or more.

Network Connectivity

While most consumer-level hard drives connect to your computer through a USB cable, some offer network connectivity, meaning you can access your hard drive from any computer or phone on the same network. That can be helpful for those with multiple computers set up and who want to use an external hard drive to back up files and transfer files between computers.

You can give any external hard drive network features by simply plugging it into your router — providing it has a compatible port — but it will require a bit more tweaking to get set up correctly. Still, special network-connected drives have some advantages.

For example, so-called Network Attached Storage, or NAS, can be used as a media server by apps like Plex, while standard router-connected drives aren’t necessarily able to do so. NAS is a little more expensive, but it’s also often expandable thanks to extra slots in the enclosure, which can accept more actual hard drives.

Ports

The kind of port or ports that your hard drive uses to connect to a computer is very much linked to transfer speed. Most hard drives connect to a computer in the form of a USB. That could mean the now-outdated USB 2.0 or the newer USB 3.0 or USB 3.1, and if it is USB 3.1, it could also connect through a USB-C connector while still using the USB 3.1 standard.

Other ports, which are increasingly less common, include FireWire 400 and FireWire 800, though fewer and fewer computers support those ports, so you should be wary of that when purchasing.

We recommend looking for a hard drive with USB 3.1 support and a USB-C connector, especially if your computer is relatively new. It might mean buying an adapter with your current computer that may not have USB-C, but when you upgrade to a new computer, your external hard drive will stay usable.

Check out our guide to the best USB-C adapters available.

Format

External hard drives come in a few different formats, though it's easy to reformat a hard drive if you buy the wrong kind. Here's a quick rundown.

NTFS is the most common format for new external hard drives and works with Windows computers. Unfortunately, it doesn't work as well with any other operating system. Macs can read NTFS-formatted hard drives but can't write to them.

HFS+, which stands for "Hierarchical File System," is a hard drive format that works much better with Macs, and it's an improvement on the older HFS format in that it can support larger file types. Unfortunately, HFS+ drives don't work with Windows computers. HFS+ drives are the way for those who plan to use them, with Macs running slightly older macOS versions.

APFS is a newer hard drive format that works with Mac computers, but it only works with Macs running macOS High Sierra or later. Like HFS+ drives, Windows computers can't read APFS drives.

exFAT is essentially a mix of NTFS and FAT32, an older drive format that's no longer in use. There are several advantages to exFAT drives — namely that both Windows and Mac computers can recognize them, so if you need support for both, it's worth formatting your drive to exFAT.

If you need help determining what hard drive format to use, use exFAT since it works with most operating systems. Though most hard drives come in NTFS, you may need to buy one and then reformat it. Remember, it can be challenging to reformat an HFS+ or APFS drive if you need to use it on Windows.

Physical Size

The physical size of an external hard drive doesn't necessarily translate to the amount of storage space, particularly with the advent of flash storage. You only have a say in the physical size of a hard drive when it comes to solid-state drives, as there are standard sizes for hard disk drives.

Hard disk drives spinning disks are either 2.5-inch or 3.5-inch sizes. A typical portable hard disk drive size is 4.35 x 3.23 x 0.59 inches. Smaller desktop hard drives come in at around 7 x 5 inches and range up from there.

Solid-state hard drives can be much smaller, making them much more portable. A fairly average size for solid-state drives is 3.79 x 1.95 x 0.35 inches.

Security

External hard drives can contain features designed to keep files more secure, which might be vital if you use yours to store sensitive information. For example, some hard drives offer password protection by default, meaning you can easily set a password to keep all your files safe.

Some also provide high-level encryption, rendering your files useless to those who don’t have your password, even if they somehow hack into the drive.

Buffer

A hard drive buffer is essentially storage between the computer and the actual storage in a hard drive. Users can access files stored by the hard drive in the buffer far quicker than those stored in the primary storage of a hard drive, and the bigger the hard drive buffer — sometimes called the cache — the better the overall performance the drive is likely to have.

Generally speaking, you only need to consider the buffer size if you run software from your hard drive. If all you’re doing is storing files, the type of drive and the speed of the disk will be much more critical.

If you need a hard drive with a larger buffer, we recommend getting one with at least a 64MB cache, though those with 128MB and even 256MB are pretty common, too.

Price

The price can vary drastically depending on the type of hard drive and the amount of storage you opt for.

Hard disk drives are much cheaper than solid-state drives, so an HDD is the way to go if you need a lot of storage at a reasonable price. You can expect to pay as little as 3 cents per GB for an HDD.

On the other hand, it's not uncommon to see a solid-state drive that runs into 25 cents per GB. Lower-capacity SSDs might cost 40 cents per GB, while 2TB SSDs might come at 20 cents. Of course, that still makes for a drive that costs hundreds of dollars.