Whether you’re shooting video on an action camera or trying to pack more apps and music on your tablet or smartphone, the microSD card you use to store your data is all-important. Whatever capacity you have never seems to be enough, leaving you high and dry while you’re on holiday or deleting files just to cram more in. Buying a bigger microSD card can solve that problem. Meanwhile, not all cards are up to every task; shooting 4K video or running more demanding tablet apps can push them too far. Here buying a faster microSD card should get things running smoothly.
Thanks to new flash memory technology, higher capacity microSD cards are now commonplace, not to mention much cheaper than they were even a year or so ago; you can pick up a 64GB card for well under £20. And if you’re looking for high performance for shooting bursts of high-speed stills or 4K video, you’re covered. Cards with write speeds of over 60MB/sec aren’t hard to find.
How to buy the best microSD card for your device
Simply choosing a microSD card can be challenging, thanks to a bewildering array of standards, which not all devices support or are even compatible with. Older devices might only support microSDHC cards with capacities of up to 32GB, though more recent devices will support this plus microSDXC, taking capacities up to between 32GB and 256GB.
What do the different speed ratings mean?
Beyond space, the big question is speed. Here things get really complex. Firstly, microSD cards have a speed class, symbolised by a number in a circle. Modern cards will be Class 4, Class 6 or Class 10, which means that the card supports a minimum sequential write speed of 4, 6 or 10MB per second (MB/sec). Class 10 cards will also have an Ultra High Speed rating, U1 or U3, symbolised by a number inside a U. U1 cards have a minimum sequential write speed of 10MB/sec, while U3 cards take that up to 30MB/sec.
Are some cards better for different devices?
Some cards now have a V (Video) rating, from V6 to V90, to claim speeds of between 6 and 90MB/sec, with a V30 to V90 card required for shooting 4K video. Others have an A1 rating for app performance, to indicate that they’re suitable for storing and running apps on a tablet or smartphone. Most cards will also mention read or transfer speeds. These won’t affect performance when you’re shooting stills or video, but will affect performance on a tablet or smartphone, not to mention the speed at which data transfers from the card to a computer.
Should I always buy the fastest card I can afford?
Is it best to buy the fastest card you can? Not necessarily. While a U3 or V60 to V90 card might be a must for 4K video recording from a DSLR or action camera, it’s expensive overkill for other devices. What’s more, sequential write speeds don’t mean anything in terms of random write speeds, which are actually more important if you’re using a card to run apps on a smartphone, tablet or laptop. Here a cheaper U1 card may be as fast and more cost-effective.
And we’re not done yet. The faster cards only deliver optimal performance on devices with slots that support the more recent UHS bus standards. Older smartphones, tablets and cameras that don’t support microSDXC may not even support the UHS-I standard, while even many newer devices won’t support UHS-II, which uses an extra set of contacts to boost speeds. If yours doesn’t, the card will still work, you could be paying extra for a level of performance you can’t reach.
In short, check what your device supports then buy according to your needs; we’ll cover how well individual cards match specific uses in the reviews below.
Which microSD cards will last the longest?
Some cards are sold as water-resistant, shock-resistant, temperature-resistant or x-ray proof, but these things are actually true of most microSD cards. However, the NAND flash memory cells used in microSD cards is susceptible to wear and tear from use. In most devices, a good card should still last many years, with most manufacturers providing solid five to ten-year warranties. However, some devices, like an in-car dashcam, will record large amounts of data every day, rewriting over and over again to the same cells and wearing them faster. For this reason and for these devices only, it may be worth looking at new ‘Endurance’ or ’Industrial’ models, which use specific flash memory cell types to lock down reliability, though often at the expense of speed.
The best microSD cards to buy
1. Samsung Evo+: The best all-round microSD card
Price when reviewed:£11.64 (32GB), £19.89 (64GB), £42.70 (129GB)
There are faster cards and cheaper cards, but the Samsung Evo+ is a great all-rounder. A Class 10 card with a U1 speed rating, it’s easily fast enough for duties in an HD action camera but versatile enough to work effectively in a tablet or smartphone. It’s sequential read speeds of 81MB/sec match those of high-performance U3 cards, while its write speeds of 35MB/sec put it ahead of most U1 rivals. When it comes to 4K Random Read/Write speeds, at 7.9MB/sec and 2.075MB/sec, it offers a stronger balance than many more expensive cards, so it’s great for smartphones, tablets and even laptops. With 32GB for under £12 and 64GB for under £20 it’s competitive on cost, and its waterproof, x-ray proof and rated for temperatures between -25 and 85 degrees Celsius. Unless you’re looking to shoot 4K video, this is the card to buy.
Key specs – Speed ratings: Class 10, U1, UHS-1; Storage capacities: 32 to 128GB; Claimed speeds: 80MB/sec read, 20MB/sec write
2. Samsung Pro+: The best microSD card for 4K video
Price when reviewed:£25 (32GB), £44 (64GB), £83 (128GB)
If you are shooting 4K video, then the Samsung Pro+ is a hard card to beat. It’s one of handful of cards recommended for the GoPro Hero4 and Hero5, and with a U3 rating and claimed read/write speeds of 95MB/sec and 90MB/sec, it has the spec to match. In tests, it’s neck and neck with similar U3 cards like the Transcend Ultimate 633x. Both cards deliver sequential read speeds of around 81MB/sec and the Samsung’s only slightly ahead on write speeds at 75.54MB/sec to the Transcend’s 73.315. The Samsung also offers higher random 4K read/write speeds, though it’s frankly wasted in a smartphone or a tablet. The reason why we’ve picked the Samsung really comes down to price; you can find a 64GB Pro+ for around £6 to £8 less than the Transcend. Given Samsung’s water, temperature and x-ray proofing, plus the ten-year limited warranty, it’s impressive value.
Key specs – Speed ratings: Class 10, U3, UHS-1; Storage capacities: 32GB to 128GB; Claimed speeds: 95MB/sec read, 90MB/sec write
3. Lexar 633x: A brilliant all-round microSD card, for 4K and more
Price when reviewed:£11 (16GB), £14 (32GB), £20 (64GB)
If you want to shoot 4K video but want a slightly cheaper card, take a good look at the Lexar 633x. It’s a U3 card with a claimed read speed of up to 95MB/sec, and it’s still recommended by GoPro for the Hero4 and Hero5 action cameras. At 78.13MB/sec it’s sequential read speed isn’t far off the pace set by pricier U3 cards from Samsung and Transcend, and while its write speed of 42.68 is substantially lower, that’s still within the requirements for 4K video or shooting bursts of high-resolution RAW photos. It’s also faster than the Samsung and Transcend competition for random 4k read speeds, though a little slower for random 4K writes. That makes it a good all-round option, and at under £20 for 64GB it’s affordable too. You can pick it up with the usual microSD to SD card adaptor, or with a UHS-1 to USB 3.0 adapter – ideal for speedy transfers to PC.
Key specs – Speed ratings: Class 10, U3, UHS-1; Storage capacities: 32GB to 128GB; Claimed speeds: 95MB/sec read, write speed not specified
4. Lexar 1000x: Class-leading read speeds for sensible money
Price when reviewed:£19.69 (32GB), £35.49 (64GB)
In performance terms the Lexar 1000x is an oddball. A Class 10, U3 device with a UHS-II interface, it still delivers slower write speeds than the Samsung Pro Plus and Transcend 633x, with a sequential write speed of 53.97MB/sec and a Random 4K Write speed of just 1.35MB/sec. It’s 150MB/sec sequential read speed, however, wipes the floor with those other cards. It won’t make much of a difference in most applications, but shoot a lot of 4K or HD video or take a lot of high-resolution stills in a RAW format, and the Lexar will get them onto your PC faster, not least because Lexar throws in a compact UHS-II to USB 3.0 adapter. In tests, 9.33GB of video files took just 73 seconds to transfer with the Lexar 1000x versus two and a half minutes on the Samsung Pro Plus. At under £36 for a 64GB card it’s cheaper too.
Key specs – Speed ratings: Class 10, U3, UHS-II; Storage capacities: 32GB to 128GB; Claimed speeds: 150MB/sec read, write speed not specified
5. Kingston Industrial Class 10 U1: The toughest microSD card around
Price when reviewed:£11 (16GB), £16 (32GB), £39 (64GB)
On paper the Kingston Industrial is nothing special; another class 10, U1 card with maximum 90MB/sec and 45MB/sec read/write speeds. It’s hardly cheap, at £39 for a 64GB card, and its performance puts it behind cards from Samsung and Transcend for shooting 4K video. The sequential write speed of 45MB/sec matches the spec, but it’s closer to the cheaper Lexar 633x. Random read/write performance is more disappointing, with both stuck at under 2MB/sec, so it’s not a great choice for smartphones or tablets. However, if you’re mainly interested in shooting video on an action camera, security camera or dashcam, then the Kingston Industrial has other advantages, including -40 to 85 degrees C temperature proofing, shock and water and x-ray proofing, plus the use of more resilient MLC NAND chips to improve reliability. Warrantied for five years and tested for industrial applications, this is one tough microSD monster.
Key specs – Speed ratings: Class 10, U1, UHS-I; Storage capacities: 16GB to 64GB; Claimed speeds: 90MB/sec read, 45MB/sec write