Wirecutter

The fastest drive we tested for transferring data to and from a computer, the Extreme Pro is also reasonably priced for the amount of storage space it offers. We prefer its retractable plug to an inevitably lost cap.

Best for Most

amazon.com

walmart

pcmag.com

expert-review

The Best USB Flash Drives

TechGearLab

The SanDisk iXpand 128GB is the best iPhone-compatible drive we've found. It offers a quick and easy way to backup files on your phone, wherever you happen to be. The SanDisk app allows you to easily select which files you want to download from or upload to your phone, and it can perform quick photo backups. Most USB/lightning drives that we've tested provide near glacial speeds, but the iXpand 128GB provides impressive speeds when using its USB connection. In our tests, it wrote a 5GB folder full of small files &mdash; the most difficult of our speed tests-- in just over 6 minutes, putting it in the top tier.
The biggest disappointment with the iXpand is that speeds are about halved when switching from the USB to the lightning connector, meaning it can take 15 minutes or more to backup 5GBs worth of photos. Also, the flexible rubber/plastic connection between the two connectors must be flexed to plug the drive into an iPhone, and we don't like the long-term durability of that connection. However, for anyone that wants a drive for transferring files to and from their iPhone, we think the SanDisk iXpand 128GB offers the best combination of performance, convenience, and price. 

The SanDisk iXpand 128GB is the best iPhone-compatible drive we've found. It offers a quick and easy way to back up files on your phone, wherever you happen to be. The SanDisk app allows you to easily select which files you want to download from or upload to your phone, and it can perform quick photo backups. Most USB/lightning drives that we've tested provide near glacial speeds, but the iXpand 128GB provides impressive speeds when using its USB connection. In our tests, it wrote a 5GB folder full of small files &mdash; the most difficult of our speed tests-- in just over 6 minutes, putting it in the top tier.
The biggest disappointment with the iXpand is that speeds are about halved when switching from the USB to the lightning connector, meaning it can take 15 minutes or more to back up 5GBs worth of photos. Also, the flexible rubber/plastic connection between the two connectors must be flexed to plug the drive into an iPhone, and we don't like the long-term durability of that connection. However, for anyone that wants a drive for transferring files to and from their iPhone, we think the SanDisk iXpand 128GB offers the best combination of performance, convenience, and price. 

Budget Pick

cnet.com

It has a funny shape but decent performance at a tough-to-beat price.

The Samsung Bar Plus 128GB perfectly fills the keychain niche for those moments when it just pays to have a USB flash drive on hand. The all-metal construction is super sturdy, and the relatively sleek design allows it to nestle onto even crowded keyrings. It is still long enough to insert it into a USB port without removing it from the keyring. It also provides good overall speed &mdash; in our tests, it wrote a 5GB folder with lots of small files in less than 4 minutes. Its read speeds are particularly impressive, meaning you can quickly access files stored on the drive. This makes the Samsung Bar Plus the perfect option for files that you don't want taking up space on your laptop's hard drive, but that you may need to access at a moment's notice. 
Our biggest issue with the Samsung Bar Plus 128GB is the hump on the drive's back, where the keyring is attached. While these extra curves lend the drive even more of a space-age feel, they also make it bulkier and less sleek than some other keychain-oriented models. However, the Samsung Bar Plus's speed and performance so far outstrips that of its competitors that it still easily gets our top recommendation for those who prefer to attach a USB flash drive to their keychain permanently. 

images-eu.ssl-images-amazon.com

For the ultimate performance per dollar, check out the SanDisk Ultra CZ48 32GB. Even with its budget pricing, it logged an impressive 166 MB/s maximum read speed in our tests, outperforming almost everything else in this price range. The drive allows for a 5GB movie file to transfer to your computer in only 30 seconds. Surprisingly, despite the drive's low price, the plastic material's quality seems reliable and strong. 
The write speeds are the obvious disadvantage to this drive, where the top performance only got up to 14MB/s during our tests. When pushing the drive even harder, speeds continued to decline. For instance, the drive took over 12 minutes when writing a 5GB folder full of modest files. However, if speed isn't a concern for you when saving things to the drive, it offers a great cost for a reliable way to save your files and access them fairly quickly when you need to.  

bazaarvoice

Now that many popular laptops and newer Android phones are moving to USB-C, it can be super convenient to have a flash drive compatible with this new port as well as the common USB-A. The only USB flash drive we have found that hits the mark in this regard is the SanDisk Ultra Dual Drive 128GB. Both connectors can be retracted at the same time, allowing it to maintain a slim profile. If you use the drive with a phone, SanDisk provides a convenient app that will enable you to do manual backups by specific file type. Additionally, the Ultra Dual Drive is much faster than other Type-A/Type-C drives that we've tested.
While this drive provides at least average speed for most file transfers, it can sometimes get bogged down when writing many small files. It took 26 minutes to write our 5GB small file testing folder. We also found the lanyard attachment annoying. It sits in the center of the drive body, is too small for a keyring, and requires a master seamstress's skills to thread. Despite these small drawbacks, for those that want both USB Type-A and Type-C connectivity, the SanDisk Ultra Dual Drive is the best option available. 

Flash Drive Comparison