Picking the right microSD card can be a challenge. With an alphabet soup of letters and numbers that represent a broad range of speeds and capabilities, it's tricky to know whether you're getting the best microSD card for your needs. Even when you stick with reputable brands, there's still an embarrassment of options available to choose from.

Choose a microSD card that's under-specced, and you'll be frustrated by slow transfer speeds, but you'll also be wasting your money if you go beyond what your smartphone, tablet, or digital camera is capable of handling. Generally, you'll want a top-tier microSD if you're using one of the best Android smartphones, especially if you plan to shoot photos and video directly onto it or use it for watching 4K movies; however, it's less necessary to push those limits if you're only planning to use it for backups or secondary storage.

Check out these microSD card options that work perfectly with your smartphone or even your favorite Android tablet so that you can keep your entire library of music and movies offline for entertainment on the go.

  • Samsung-Evo-Select-MicroSD-Card
    Samsung Evo Select microSD card
    Best overall

    Samsung may be best known for its Android handsets, but it’s also one of the biggest flash storage and microSD card makers on the market. The Evo Select has a maximum sequential read/write speed of 130MB/s, which is more than fast enough for your 4K video recordings on your phone. Depending on the retailer, you’ll either find the Evo Select or the Evo Plus. They are just different brandings for the same product.

  • Lexar-Professional-1066x-MicroSD-Card
    Lexar Professional 1066x microSD card
    Premium pick

    Most of Lexar's memory offerings focus on photo and video cameras, which usually prioritize high sequential write speeds. This one is a little different, as its A2 IOPS rating means it can load, update, and manage apps with the best of them. It won't match a phone's internal storage speed, but it's perfect for playing graphically intensive games requiring much storage space. As far as sequential reading and writing speeds go, it's on par with the pack.

  • PNY-Pro-Elite-MicroSD-Card
    PNY Pro Elite microSD card
    Best value

    If you only need 128 or 256GB of storage expansion, the PNY Pro Elite deserves your consideration. It lives up to its A2 rating by quickly loading non-critical apps like games and messenger suites. Despite its affordable price, its overall performance is nearly on par with the best. However, if you need a 512GB or larger microSD card, you'd be better off with our Premium Pick, as this particular lineup at higher storage capacities may not offer the reliability you need.

  • Samsung-Pro-Plus-MicroSD-Card
    Samsung Pro Plus microSD card
    Upgraded option on a budget

    If you own a relatively recent flagship smartphone and want to get the highest speeds out of your expanded storage, consider the Samsung Pro Plus. It exceeds all the qualifications required for the V30 and A2 standards, and each size performs similarly well, which isn't always the case with high-capacity microSD cards. The only knock against this one is that it's slightly more expensive than other options. However, that's a minor downside against the additional performance gains.

  • SanDisk-Extreme-MicroSD-Card
    SanDisk Extreme microSD card

    The SanDisk Extreme model got a refresh in 2022 that introduced SanDisk's QuickFlow technology, enabling read and write speeds of up to a staggering 190MB/s and 130MB/s, respectively. This is one of the best write speeds you can get on a microSD card that doesn’t cost a bomb. However, you should avoid going for a capacity lower than 128GB to ensure you’re getting the best out of your microSD card. A lifetime warranty is also included.

  • Kingston-Canvas-Go-Plus-MicroSD-Card
    Kingston Canvas Go! Plus

    Kingston has been manufacturing high-quality memory of various types for many years. That tradition continues with the Canvas Go! Plus microSD card, which boasts respectable 90 and 170MB/s write and read speeds, respectively. It's great for recording 4K video and loading apps with little to no waiting time. Kingston also makes another lower-tier microSD card for a few dollars less, indicating Canvas Go! Plus’ flash memory is even more reliable than the rest of Kingston's already dependable offerings.

  • Transcend-Ultra-Performance-microSD-card
    Transcend Ultra Performance microSD card

    The vlogger in you will appreciate having this microSD card from Transcend, which is designed for stressful tasks like continuous video recording in 4K resolution. Even your new gaming phone could benefit from its fast read and write speeds. Unlike many other cards, the Transcend Ultra Performance’s write speeds are pretty close to its impressive read speeds, speeding up your file accessibility. What’s even better is that it’s priced quite well for the 256GB variant.

  • Lexar-E-Series-microSD-card
    Lexar E-Series microSD card

    For basic use, you can easily get away with the entry-level Lexar E-Series card available in sizes starting from 32GB and going all the way up to 512GB. It still meets all modern microSD card standards, making it perfectly capable of recording 4K videos. However, its write speed of 30MB/s may not be suitable for applications that need faster storage. Lexar has more than made up for it by making the card durable and throwing in a respectable 10-year warranty.

What happened to microSD card slots?

Unfortunately for consumers, smartphone manufacturers have discovered they don't make any money from microSD card expansion slots. By comparison, they make plenty of scratch by selling multiple tiers of their flagship devices with varying levels of internal storage. Every 128GB of internal storage from microSD expansion is 128GB of storage that the phone manufacturer won't see any money from. That's why Samsung lets you upgrade to 256GB of storage on the Galaxy S24 for $60, while Apple asks for a hefty $100 for the same storage upgrade on the iPhone 15.

If you're absolutely attached to massive amounts of internal storage, you should be prepared to spend out the wazoo for a high-end flagship. However, you can also avoid flagships altogether and go for midrange or budget-friendly smartphones.

How much do speed class ratings matter?

Actually, not much. Combinations of letters like U3, C10, UHS, and others grace the front of nearly every SD card on the planet. These refer to the minimum speed a flash memory card can achieve instead of the maximum. C10, for example, means a card can write large sequential files at 10 megabytes per second or faster. But, of course, 10MB/s isn't very fast, which is evidence that some of these numbers are redundant or obsolete, and none of them give you a 100% accurate snapshot of an SD card's actual speed in real-world use.

Of our favorite microSD cards, the Lexar 1066x has just about the best speed ratings without costing an absolute fortune. And the SanDisk Extreme and Extreme Pro come close to real-world benchmarks and cost considerably less.

U3 and V30 microSD card ratings

Not to be confused with UHS-I and UHS-II, U3 stands for UHS Class 3, which is identical to the V30 rating of 30MB/s minimum write speeds. In theory, that's fast enough to record compressed 4K video at 120 frames per second, but outside of Sony's high-end Xperia line, Android devices aren't equipped to do that for long periods of time. The U3 and V30 ratings are a decent target for anybody in search of consistently fast microSD storage.

A1 and A2 microSD card ratings

Established to give consumers an idea of how a microSD card stands up to everyday app usage, A1 and A2 are more recent introductions than other speed classes. Rather than pure write and read speeds, they measure minimum input/output operations per second (IOPS). IOPS is an important metric for searching, loading, altering, and reloading lots of small files at once. In other words, you want a high IOPS rating if you plan on loading any apps from a microSD card.

Quality Android devices with microSD slots can often take special advantage of TF cards with A1 and A2 ratings; these are becoming more commonplace, even as fewer high-end phones include memory expansion slots. A1 denotes a card rated for 1,500 read IOPS and 500 write IOPS, while A2 ups those figures to 4,000 IOPS and 2,000 IOPS, respectively.

Storing apps on microSD cards is a definite no-no

While most high-end phones don’t come with a card slot anymore, it wouldn’t be a good idea to store apps on the microSD card even if your phone does have one. Modern apps have become far more complex than they used to be back in the day, and they now rely on super fast storage to get you the snappy performance you expect from your phone. Even the highest-end microSD cards just can’t keep up with those requirements.

The A2 standard for microSD cards allows for up to 4,000 read and 2,000 write IOPS. On the other hand, the UFS 3.1 storage used on most phones can hit a staggering 100,000 and 70,000 IOPS, respectively. This stark difference will be quite evident in your everyday usage, and the divide is going to get wider as we prepare for the UFS 4.0 standard. You’re better off using the removable storage for your media files while keeping apps running off the internal storage for optimal performance.

Are there any 2TB microSD cards?

Some Android devices support storage expansion up to 2 terabytes, but there aren't yet any microSD cards from major reputable brands with that kind of capacity. Mass production of 2TB microSD cards was expected to begin in 2023, but we're only just now seeing the very first ones announced in early 2024, starting with AGI's Supreme Pro TF138, which is expected to sell for upwards of $200.

Beware of counterfeit microSD cards

A quick search of most online retailers will show you a handful of microSD cards with ridiculously low prices. We're talking about 1TB models in the neighborhood of $20. Do not trust these "great" deals under any circumstances. Every single one will leave you disappointed.

Some big online stores put all their supposedly similar products together, regardless of whether they're sold directly by the retailer or by a third-party vendor using the retailer's platform. For example, when you buy a microSD card that's "Sold by Amazon," it almost certainly comes from a single bin that contains a bunch of the same models sold on Amazon but from alternate vendors. While all the models in that bin might look the same, some of them are counterfeit.

If a deal from an unknown seller looks too good to be true, then it most likely is. There is a good chance that you'll end up getting a fake product in the box. If you’ve already received your package, there are a few ways to check if your microSD card is authentic, even though counterfeit cards are making identification more difficult every day.

Firstly, scan the packaging for its print quality and typos. Next, you can check the card itself. While the printed icons could be perfectly copied, counterfeit cards sometimes cannot match the brand’s original color. You can check for these anomalies against the original images on the brand’s website. Lastly, fake cards often overstate their storage size and even trick your computer into showing an inflated figure. You'll be able to detect this if the card starts to fill up faster than expected or by using software like FakeFlashTest. Luckily for consumers, most major retailers are very good about replacing counterfeit flash memory.