How to choose the best MicroSD cards for your smartphone or tablet

If you run out of storage space on your phone or tablet, then you’ll want to find a way to get more. One of the simplest options is to insert a MicroSD card. Sadly, not all smartphones and tablets support MicroSD cards. If you have an iPhone or iPad, then you’re out of luck, but many Android devices do support them, as do some Windows Phone and BlackBerry handsets.

More: How to set up and use a MicroSD card on your Android phone

Check the full specs for your phone on the manufacturer’s website, or look for a MicroSD card slot in your phone. On newer phones, the’re generally part of the SIM tray.

What to consider when buying a MicroSD card

There are a handful of things to consider when you’re choosing a new MicroSD card for your phone. Obviously, the price and capacity are going to feature, but you also need to make sure that the type of card you buy is supported by your device and that it’s suitable for your needs.

SDHC and SDXC

SDHC stands for Secure Digital High Capacity and SDXC stands for Secure Digital Extended Capacity. The only real difference is the range of data they can store. You’ll find that SDHC MicroSD cards range from 2GB to 32GB in size, while SDXC MicroSD cards range from 32GB up to 256GB in size.

Class and UHS ratings

The Class rating of a MicroSD card refers to its minimum transfer speed. UHS stands for Ultra High Speed. Here’s how the minimum speeds for different classes break down.

Class
Minimum Speed
2
2 MB/s
4
4 MB/s
6
6 MB/s
8
8 MB/s
10
10 MB/s
UHS 1
10 MB/s
UHS 3
30 MB/s

Most MicroSD cards are a lot faster than the minimum speed. A Class 10 card may offer 95 MB/s, for example, and UHS cards can go up to 312 MB/s.

Application Performance Class

The SD Association also recently unveiled a new standard, called App Performance Class, which is designed to highlight MicroSD cards that are suitable for use in smartphones and tablets. The A1 rating means that the card can manage random read input-output access per second (IOPS) of 1,500 and write IOPS of 500. This is ideal for quickly opening apps and processing tasks. These new A1 cards are worth looking out for if you intend to format your card as internal storage in an Android device, something Google calls “Adoptable Storage.”

How to choose a MicroSD card

You’re obviously going to want the highest speed, highest capacity MicroSD card you can get, for the lowest price. We would advise you to factor in the brand reputation and the reported performance and reliability. Check out the warranty terms, just in case something should go wrong. You also need to be careful where you buy. If you’re going to use Amazon or eBay then read some customer reviews and watch out for fake MicroSD cards, because they’re disappointingly common.

We’ll highlight a few MicroSD cards worth buying on the next page. Always make sure that you check compatibility with your device before pulling the trigger.