The best microSD cards

There are hundreds to choose from, memory card, but does it matter which card you buy to expand your device’s storage? We tested some top brands to find out

Memory cards – better described as storage cards, since they keep data permanently, not temporarily like RAM – come in a number of formats, but the fingernail-sized microSD is now the norm in phones, tablets and action cameras, and are even starting to appear in laptops.

Capacity (in gigabytes) will be the first number you look at, but compatibility and performance also matter. Older cards were rated Class 2,4 or 6 (shown as a digit inside a letter C) for the number of megabytes they could write (ie. record) per second (MB/s).

These days, you’re more likely to see Class 10 cards, labelled with a 1 or 3 inside a U: U1 cards write up to 10MB/s, while U3 reach speeds of 30MB/S. The newest devices support ultra-high-speed cards: UHS-I (up to 104MB/s). UHS-II (312MB/S) or, rarely, UHS-III (624MB/s). These are shown on the card as Roman numerals.

For video, write speed is crucial for smooth recording – your camera’s manual or website will advise. Read speed indicates how fast the data can be recovered, such as playing a video.

To expand a smartphone or tablet, any U1 card should be fine, so don’t spend more than you have to. For a laptop, you might want a bit more speed.

Many microSD cards come with an adapter for a full-size SD slot. This won’t reduce performance, but if you use a microSD card regularly in a full-size SD device, it’s just another connection that might fail.

Samsung Pro+

Cameras that shoot 4K video need high write speeds. This U3/UHS-I card from Samsung matched others of the same class rating in our sequential tests, which reflect video use. reading at up to 81 MB/s and writing at 75.5MB/s.

Samsung Pro+

It beat rivals in our random read/write tests, which are more taxing and better reflect use in a smartphone, tablet or laptop, but in fact this card is so fast it’s overkill for those purposes. Even phones that shoot 4K don’t usually need extreme speed, because they use relatively low bit rates. A few cameras, on the other hand, need faster cards even for 1080p Full HD at high bit rates. Check your manufacturer’s advice. But for most video users, reasonable prices and a limited 10-year warranty make the Pro+ a good buy.

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Samsung Pro Plus 64GB MicroSDXC Memory Card --- 95MB/s Read, 90MB/s Write

Last update was on: June 18, 2024 1:30 pm


Not everyone needs to pay this much for storage, but where speed matters, the Pro+ is a great choice at a fair price


Lexar 633x – GoPro SD Card

This Ul card claims the same maximum write speed as the U3 Samsung Pro+, at 95MB/s. In our sequential read test, how’ever, it only managed 78.1 MB/s. and its write speed of 42.7MB/S was much slower. That’s still sufficient for typical 4K recording. The Lexar 633x is recommended by GoPro for its Hero4 and Hero5 action cameras. With random files – to reflect use in phones, tablets and laptops – it was a little faster than both of the Samsung cards w’hen reading but a little slower when writing.

Lexar 633x

Considering the modest prices, this is pretty good performance, and it’s available with a choice of a full-size SD card shell or a USB 3.0 adapter. The latter will be handy if you use the card in a camera or mobile device and need to transfer photos to a PC.


It’s not as fast as we might hope, but adequate for even demanding purposes and overall a good-value mid-range option

Rating 4/5

Lexar 1000x

This U3 card uses the faster UHS-II bus (which your device needs to support), but in our tests it was slower to write than the Samsung Pro+, at 54MB/s for sequential writes and just 1.35MB/S for random.

Where it scores well is in sequential reads, reaching 150MB/S. That’s not much help in most real-world situations, but the best case for buying the Lexar 1000x is if you shoot a lot of video or high-res stills on a digital camera and then need to import them to your PC.

The card comes with a USB 3.0 adapter to take advantage of its read speed, and could save you a lot of time. We transferred a 9.33GB video file in one minute 13 seconds, much faster than the two minutes 30 seconds it took with the Samsung Pro+.

Rating 4/5


Performance is heavily weighted towards read speeds, but if the write speed is enough for you, the faster importing will be a welcome bonus

Kingston Industrial Temperature Card

For a U1/UHS-I card claiming up to 90MB/S read and 45MB/s write speeds, this looks pricey. Although it did live up to that 45MB/S in our tests it was pretty much equalled by the cheaper Lexar 633x. In random reads and w’rites it fell to under 2MB/s.

So what’s so special about it? Well, the NAND chips that all microSD cards are based on come in different varieties, and the Industrial Temperature Card uses the more resilient MLC type. That helps Kingston to guarantee it’ll work at temperatures up to 85 degrees Celsius and down to a teeth-chattering minus 40, as well as surviving water and X-rays. Kingston also claims it’s shockproof, but we’ve never broken a microSD card by dropping it. If you need a card for your outdoor security camera, it’s one to consider.


The enhanced resilience will suit a few users, but for general phone or tablet expansion it’s not the best deal around

Rating 3/5

Winner: Samsung Evo+



There are faster cards and cheaper cards, but this one is a great all-rounder for the money. That’s exactly w’hat we’d expect from Samsung’s Evo range. The Evo+ microSD is a Class 10 card with a U1 speed rating, which is more than adequate for general use in a phone or tablet, and sufficient for an HD action camera. In our tests, its read speed topped out at 81 MB/s and write speed at 35MB/S, putting it ahead of most U1 cards.

Our more challenging 4K random read/write tests cut these figures to 7.9MB/S and just over 2MB/s respectively – a more balanced performance than many pricier cards. So even fora laptop, where Window’s might be reading and writing data in random chunks, you won’t be disappointed.

We’re not overly concerned about manufacturers’ claims of durability or ruggedness, because SD cards are pretty indestructible anyway, but this one does promise to resist water. X-rays and temperatures from minus 25 to 85 degrees Celsius – so just don’t boil it. As long as you’re not shooting 4K or high-bitrate video, it’s a good choice.


There isn’t a single microSD card that will be right for every purpose, but this will suit a lot of people at a very reasonable price



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