8094 Votes

Micro SD Memory Cards: Difference between microSD, microSDHC, microSDXC and microSDUC

Info by Collin McNeil | Last update on 2022-12-25 | Created on 2014-03-19

Currently I am looking for a new microSD memory card for my smartphone. When looking through the offers from Amazon, I came across some cards that were marked as microSDHC or microSDXC, others where titled classically as microSD.

When starting, it was not easy for me to find my way through this jungle of different terms. However, by now, I have researched and I would not deprive you of my findings.

First of all, it is important to know, that microSD, microSDHC as well as microSDXC and microSDUC cards are just completely normal microSD cards. There is only a difference in the storage volume of the cards:

  • Micro SD - A classic microSD has a maximum of 2 GB of storage
  • Micro SD HC - The memory of a microSDHC is between 4 and 32 GB
  • Micro SD XC - The memory of a microSDXC is between 32 GB and 3 TB
  • Micro SD UC - The memory of a microSDUC is between 2 TB and 128 TB

HC, XC and UC are merely abbreviations for High Capacity, eXtended Capacity and Ultra Capacity and give information about how much memory is available on the microSD flash memory cards. I was so confused for nothing.

Compatibility

Even if microSDHC, microSDXC and microSDUC cards are normal Micro SD cards, you still have to watch out that the cards are compatible with the device, in which you would like to use them. Here you should definitely look into the manual before purchasing a memory card.

Some old Micro SD cards are still formatted with the old FAT16 file system, the Micro SD HC cards are usually shipped with FAT32 and the Micro SD XC as well as the UC cards with the brand new exFAT system. So, if you have an older smartphone or an older digital camera, you have to pay attention to whether the appropriate file system or the storage size are supported by your device at all.

In this regard, roughly you can consider the years when the individual formats have been released: the SDHC format was presented in 2006, the SDXC format in 2009 and the SDUC format in 2018. Devices that are older than a certain format, will probably not automatically support this format.

However, in some devices, also newer cards should have been made running by simply formatting them in another file system. But this way must not work in every device.

Class 2, 4, 6 and 10 Memory Cards

Another difference between Micro SD cards is the classification in Class 2, Class 4, Class 6 and Class 10.

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5664 Votes

As a 72 year old novice - but game to learn, I was thinking as I look at all the letters, I wish I knew what the letters SD, HC, and XC meant so I could not only remember them (sadly an issue at 72!), but it would help me understand what I was looking at.

I thank you so much for including those explanations in your answer and for the compatibility warning. I feel very smart at the moment. I am bookmarking this page for all my needed tech answers….and will search for your answers when looking as I see there are many contributors to this site.

Much appreciated, Collin.
2014-12-30 at 17:37

ReplyPositive Negative
812 Votes

We have this problem at a quarter of your age.

You get respect that you searched and found the answer.
2016-02-29 at 05:54

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610 Votes

Im an old guy too with memory problems. Can I fix my organic cerebral memory with on of these SDXC cards? Now that will be advanced tech!!
2016-03-19 at 16:04

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-5561 Votes

SD stands for SanDisk, which is the company that orginally developped this type of memorycards.

HC - high capacity
XC - eXtended capacity
2015-04-17 at 14:36

ReplyPositive Negative
5769 Votes

No. That is not correct. SD stands for "Secure Digital" (Memory Card).

If you don't trust me, look up "SD Association" or "Secure Digital" on the Internet.

SanDisk Cooperation is part of the SD Association, but why should companies like Toshiba, Samsung, HP or Panasonic build SD cards if SD is standing for SanDisk?
2015-04-18 at 11:54

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-519 Votes

I am in my 76th year, but hopefully a little tech savvy, & I have found that there are different explanations for SDHC & SDXC Micro cards, usually the SDHC is quoted as being for the latest smartphones, where as the SDXC is quoted as being for high capacity DSLR Cameras, which tend to hold a higher quality photo than a cell phone camera does.
2015-05-19 at 17:38

ReplyPositive Negative
06 Votes

Hey, do you know that you can retrieve the missing capacity of your SD?

For example, you bought a 64 GB SD, and when you read it, it only shows 59.4 GB....

There is 100% way to recover the missing 4.6 GB.
2016-01-14 at 01:57

ReplyPositive Negative
13 Votes

No need to worry about that. This is just because of a different kind of counting the bytes.

If you want to know it in detail, see the discussion about why USB sticks are showing less memory than specified.
2016-01-15 at 03:50

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02 Votes

Good to know that -MANY THANKS-, but if you had included information on how to do it would have been much better.
2016-03-05 at 19:47

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22 Votes

The SD card, like a disk drive, has to be formatted for computer system, like little compartments to store your data blocks or files. Each compartment has an address like your mailbox so the computer can find the file again quickly.

Without some for of addressing it would have to start at the beginning and search sequentially to the end every time you access the SD card so they set up a File Address Table (FAT), like an index for a book, to speed things up and organize your files.

This is why the "available" storage is always lower than the maximum shown but the good news it shows your SD card is formatted and working.

Of course you can have 100% capacity by removing the formatting but you will not be able to use the SD card for anything until you format it again to suit your computer, tablet, phone or camera and some vary which is why manufacturers sometimes ask you to install a new SD card or re-format a previously used one to make sure it works.
2016-08-18 at 01:33

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00 Votes

That was an outstanding, understandable description of the FAT file system. Can you tell us about the exFAT file system?

Explanations that are understandable to those without even some expertise in a matter are rare - and yours was excellent!
2021-02-20 at 22:33

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11 Vote

Hello Everyone!

All right you Folks, I'm a 62 year old blissfully retired old fart. I just bought a just for reading tablet and it has a "TF Card". Is that just an old SD card? I'm not sure of the max my new tablet can hold and I need to contact the mfg. However, I came along this post and thought you'd all want to throw this into the mix and see what comes out ;0) Also, give the info here, do you think that a SDHC disk will be compatible (that is if max size is high enough). You all ROCK!!!

Sincerely, Sharon "Live'n here in Allentown"
2016-11-28 at 17:19

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