Best 128GB USB Flash Drives: 10 Ranked, and the Write Speeds the Boxes Hide

The SanDisk Ultra takes first place among the best 128GB USB flash drives because it is one of the few listings here that give a read speed and a lower, separate write speed: 130 MB/s read, 80 MB/s write. In practice, the 80 MB/s is the number that governs how long a file takes to copy onto the drive. Which means the full-length film it claims to transfer in less than 40 seconds is being timed at 130 MB/s, not at the write speed you will actually get.

The drive is USB 3.0, backward compatible with USB 2.0, and SanDisk claims up to 10x the speed of a standard USB 2.0 stick. It carries SecureAccess encryption and password protection, measures 22 x 11 x 8 mm, and is sold in 16 GB, 32 GB, 64 GB, 128 GB and 256 GB. The rating is 4.6 from 210,343 reviews, with 77% of them five-star and 1% one-star.

That said, 80 MB/s write is mid-range, not fast. Anyone shifting large video files regularly should look at the dual-port Amazon Basics, whose 400 MB/s read is the highest figure here - but note that Amazon publishes no write speed for it at all. And if your laptop or phone takes only USB-C, this Type-A drive is the wrong shape.

At £11.99 this is the second-cheapest 128GB USB flash drive in the list and the best-reviewed of the budget group: 4.4 from 68,396 ratings, 70% of them five-star. The problem is in the specs. The write-speed field reads '2x', which is not a speed, and the flash memory type reads 'SD' on what is a USB stick, not a memory card.

In use it is a plain USB Type-A drive: USB 3.2 Gen 1, a protective cap rather than a retractable body, a large loop that takes a keyring, and a listed weight of 11 g. Kingston lists it as shockproof, and the colour varies with the capacity.

Worth noting: 7% of its ratings are one-star, the joint-highest share of any drive in the top half of this list. The cap is a separate piece that can be lost, there is no USB-C connector, and with no usable write figure you cannot tell how it compares with the SanDisk Ultra's stated 80 MB/s before you buy.

By contrast with the Ultra, the Ultra Flair prints 150 MB/s on the box - and then reprints the same 150 MB/s in the write-speed field of its own data sheet. A USB 3.0 stick does not write at the rate it reads. The catch is simple: the 150 MB/s headline is a read figure, and the identical write number is a copy of it, not a measurement.

The Flair costs £19.00, a penny more than the plastic Ultra, and swaps plastic for a metal casing. It adds a year's RescuePRO subscription for recovering deleted or corrupted files alongside SecureAccess encryption, and claims transfers 15x faster than standard USB 2.0. Its manufacturer field names Amplim rather than SanDisk, and the country of origin is given as the USA.

Buy the Flair if you want the metal body and the recovery software. Skip it if you are comparing the best 128GB USB flash drives on write speed, because the listing never states one you can trust - the Ultra's 80 MB/s is the figure SanDisk will actually stand behind.

This drive shows the clearest read-versus-write split of the ten: 130 MB/s read against 30 MB/s write. That is a gap of 100 MB/s between two figures in the same data sheet, and it costs £27.71 - more than the SanDisk Ultra, which quotes an 80 MB/s write.

It is a telescopic USB 3.1 flash drive, so there is no cap to lose, and it works in USB 3.0 and USB 2.0 ports. In practice it is a 128GB USB flash drive for laptop and desktop use: NAND flash, plug-and-play, 8.49 g, ranked 51st in Amazon's USB flash drive chart. Amazon also states that usable capacity is above 115 GB, below the 128 GB on the label.

As a result, 30 MB/s write makes this a poor choice for large video files, even though the read figure looks strong. And at £27.71 it is the second most expensive drive here, which is hard to justify when the SanDisk Ultra writes at a stated 80 MB/s for £18.79.

In theory the dual-port Amazon Basics is the fastest drive in this round-up: 400 MB/s read over USB 3.2 Gen 1, whose 5 Gbps ceiling allows for it. But no write speed appears anywhere in the listing, and one bullet admits that read and write speeds vary with the device used, the file size and the file type.

The point of it is the two connectors: USB-C and USB-A on a rotating metal body, formatted exFAT so it moves between phones, tablets and computers without reformatting. It is not compatible with the Lightning port, and Amazon again notes usable capacity above 115 GB rather than the full 128 GB on the label.

Even so, £35.31 is nearly double the SanDisk Ultra, making it the highest price among the best 128GB USB flash drives here, and you are paying it without a published write figure. The 4,759 ratings at 4.6 are also the smallest sample in the top five. If what you actually do is copy files onto the drive, this is a lot of money for one verified number.

However you read this listing, the numbers on it do not describe a 128 GB drive: the Cruzer Blade is USB 2.0, its read-speed field reads '1 Bytes Per Second', its flash memory type reads '16', and only the write field gives a usable figure of 30 MB/s. Yet it is one of the best-reviewed items here at 4.6 from 286,586 ratings, the largest review base among the best 128GB USB flash drives on this page.

At the same time, the drive itself is a straightforward budget stick: compact enough for a pocket, drag-and-drop, with 128-bit AES encryption and password protection through SanDisk SecureAccess, and it works on desktops, laptops, tablets and mobile devices.

The reason to skip it is the interface. USB 2.0 caps real transfer rates well below a USB 3.0 128GB flash drive, so a large file set will take far longer than on the £18.79 SanDisk Ultra. Buy it for documents and photos; do not buy it for video.

£41.99 buys two drives, so roughly £21 per 128GB USB stick, each rated at up to 100 MB/s read. No write speed is published anywhere. Crucially, the listing contradicts itself on quantity: the spec sheet lists Number of Items as 3 and Number of Packs as 2, on a product named as a 2-pack. Check what arrives.

Each stick weighs 7.41 g, has a push-button retractor and a lanyard loop, uses USB 3.2 Gen 1 over Type-A, and includes Lexar's DataShield encryption, which creates a password-protected safe and securely erases anything deleted from it. No software installation is needed.

That said, 100 MB/s read is the joint-lowest figure among the USB 3.0 and 3.2 drives here that state a read speed, and with no write number the £41.99 is being spent on a partial spec. Buy the pair if you want one drive at home and one in a bag; buy a single, faster drive if you only need one.

The Gigastone's write-speed field contains a sentence - '[Faster than USB 2.0]' - instead of a figure, which makes it hard to rank against the best 128GB USB flash drives that do publish a write speed. Its read speed is given as 100 MB/s and it costs £28.99. The listing is also inconsistent about the interface: the title says USB 3.0, the box contents say USB 3.2 Gen1.

What is consistent is the design: a capless retractable body in carbon-fibre style, listed as lightweight, shockproof and X-ray proof, working in both USB 2.0 and USB 3.0 sockets on PC and Mac, with Windows 7 through 10 and Mac OS supported. It weighs 13.6 g.

Either way, the evidence base is thin. Its 327 ratings are the second-smallest sample here, ahead of only the LinkMore, and 7% of them are one-star against 70% five-star. The listing also carries the standard notice that international products ship from abroad with separate terms.

At £11.19 the LinkMore is the cheapest drive in this round-up, and it is a USB 3.2 128GB drive with a 5-year warranty. It is one of the few here that state both speeds: 120 MB/s read and 60 MB/s write, which is 20 MB/s slower on reads than the SanDisk Ultra and 20 MB/s slower on writes.

Its own labelling does not agree with itself - a bullet says USB 3.1 Gen 2x1 while the spec field says USB 3.2 Gen 1 - but either way it is a Type-A stick, 8 g, listed as vibration proof and compatible with Windows 7 to 11, Linux kernel 2.4 and later, and Mac OS X 10.8 and later.

That said, 235 ratings at 4.3 is the thinnest evidence base in this list, with 6% one-star and 5% two-star. If you want a cheap second drive for documents, the stated 60 MB/s write makes it a better budget pick than the USB 2.0 Cruzer Blade at £14.99.