SD vs. SDHC vs. SDXC - Here's The Best SD Card!

You've probably come across a memory card before. But if you have ever looked at a card that was called something like "Micro SDHC card 32GB w/adapter V30 A1 (UHS-3)" - and thought "Is that the one I need?", then this is guide for you.

What is the difference between SD, SDHC and SDXC? SD stands for Secure Digital, HC stands for High Capacity and XC stands for Extended Capacity. The difference between the three is the storage capacity. SD is the smallest memory card, and SDXC has the largest storage space.

In this blog post, I will explain what all the different terms mean and what to look for when looking for a memory card for a specific need.

In the video below, my colleague gives you a guide to SD cards.

Best SD card » SD vs. SDHC vs. SDXC. What do these terms actually mean?

SD stands for Secure Digital and is a memory card that is used to store data in e.g. cameras, GPS and other electronic devices.

It can be practical when photos are not store on a hard drive inside the camera, but stored on a small card that can be removed from the camera or phone, so that you can easily transfer photos to the computer directly from the card.

You can get both SD, SDHC and SDXC cards, as well as micro versions of the cards. The difference between SD, SDHC and SDXC is that SDHC has a larger storage capacity than SD, and SDXC has a larger storage capacity than SDHC.

SDHC stands for Secure Digital High Capacity and unlike SD cards, which officially have a maximum capacity of 2 GB, SDHC cards can store up to 32 GB.

SDXC stands for Secure Digital Extended Capacity and supports up to 2TB of data.

The difference lies in the way the data is stored and read. You can't be sure that a camera that supports SD can read an SDXC memory card, so when buying memory cards, check first what your camera supports.

Be aware that if your devices normally use SD cards, you cannot expect them to be able to handle SDHC size cards if they exceed the 2 GB limit. The card will probability work, but the full capacity cannot necessarily be used.

The best card is therefore the fastest card in the category that your device supports.

Another difference between SD, SDHC and SDXC is that the data is read and written at a higher speed.

You will also find a type of memory card called CF (Compact Flash) card. These cards are available in sizes up to 32 GB. The CF cards are an older format that many SLR cameras use. However, the vast majority of newer cameras also have slot for an SD card.

If this is the case for your camera, you will be able to store images on two cards simultaneously. CF cards are relatively large and square, while SD cards are quite small and rectangular.

Micro SD - Memory card in Micro size

There is also a type of memory card that is about a quarter of the size of SD cards. They are called Micro SD card cards, and like the SD cards, they come in a Micro SD, Micro SDHC and Micro SDXC version.

Micro SD was developed based on a desire to make the cards smaller so that they could be used in e.g. mobile phones, but they are also used in smaller cameras and several types of other electronics.

SDHC and Micro SDHC, as well as SDXC and Micro SDXC, are based on the same technology, so most Micro memory cards come with an adapter so you can use a Micro SD card with an adapter in equipment that uses SD.

If a memory card is rated Micro SDXC, then it will work with all devices that support the SDXC format, but you may need an adapter for the card to fit in the device. Conversely, you cannot use an SDXC card in a device that uses Micro SDXC, as it will be far too large for the SD slot.

The terms therefore refer to the physical size of the card, how data is stored on the card and how large the capacity of the card is.

Which SD card should I choose for my phone?

Android mobile phones typically use Micro SD/-SDHC/-SDXC cards. If you take a lot of pictures and your phone does not have a large internal capacity, you should choose a card with as large a capacity as possible.

Memory cards are typically available in 16 GB, 32 GB, 64 GB, 128 GB, 256 GB or 512 GB variants. They are also available with larger capacity, but they are not as common.

You can also use the memory card to transfer music files to, which you can then play on your phone.

Look for the A1 Label for mobile

If you want to be sure that the memory card is good for use in the mobile phone, look for the A1 labeled. Some manufacturers have started to put a label - A1 - on the memory cards, marking that the card is suitable for use with smartphones.

If the card has the A1 label, you will also be able to save apps on the memory card and use them directly from the card on your mobile. It is smart if you have a mobile phone that does not have a large capacity.

If you buy an A1-labeled card, you increase the memory on your mobile phone with the extra GB that the card supports.

Best memory card for camera

If, on the other hand, you need a memory card for use in a video camera, then look for which video class the card supports.

As video cameras get better and better, and with higher and higher resolution, it also requires a memory card that can read and write the data at lightning speed and has a high capacity.

The manufacturers of memory cards try to comply with this by dividing the cards into different video classes - according to what they are suitable for.

V6 supports SD video and 720p video recording

If the video classes show speed – what is the UHS classification?

UHS is also a term for speed. The video classes can be a bit confusing, because the cards are already divided into categories – the so-called UHS classification.

But where the video classes show how good a card is for storing video recordings, the UHS class is a more general term for how fast the card is for storing data.

The higher class a card has, the faster it can store data.

For example, a UHS Class 10 card can store at 10 MB per second, while a Class 8 can store at 8 MB per second, and so on.

Note that there isn't an official class above 10, but that doesn't mean you can't get cards that store faster than 10MB per second. There's just no official term for them.