Memory cards give you extra storage in your phone, DSLR camera, tablet or laptop. They’re versatile, cheap ways to store more photos, videos and music on your device.
SD cards have been around since the 90s. In that time (as with all technology), they have evolved into different formats, memory capacities and designs. Now they fit in your phone and have other formats for different uses.
This is your all-in-one guide to SD cards and micro SD cards so you can shop smarter and understand what your memory is capable of.
SD card
SD cards are the original Secured Digital cards that went up to 2 GB. At the time, this was a high capacity that worked great for digital cameras and other applications. Over time, our data needs grew.
For modern context, 2 GB is the rough estimate of 1:20 of streamed 4K content like a movie or TV show, just to show how far we’ve come regarding our data requirements.
Here’s a look at our favorite SD card.
SDHC card
These are Secure Digital High Capacity cards. As you might have guessed, these have more capacity than standard SD cards. They have 16 times more storage.
SD cards max out at 2 GB. SDHC cards max out at 32 GB. They were terrific when introduced because you didn’t have to buy a bunch of separate cards, label them and find a way to organize them.
As we’ll explain in a minute, there have been even more significant advancements in storage capabilities that many of us didn’t think were possible for a while.
If SDHC is all you need, we recommend this 3-pack from SanDisk with 32 GB of space per card for a dirt cheap price (even when it’s not on sale).
SDXC
Consider SDXC to be the next evolution of SD cards. This stands for Secure Digital Extended Capacity. These newer cards allow for exceptional capacities. SDHC cards capped out at 32 GB when SDXC was introduced. However, SDXC can surprisingly hold up to 2 TB (2,048 GB) in a small, confined package.
SDXC also allows for greater transfer speeds. If you were transferring a lot of data from your SDXC card to your PC, the data transfer rate is how many bits it can transfer in a single second.
At the standard rate of 312 Mbps, you can transfer thousands of high-resolution photos in a matter of seconds and move a high volume of data without sitting there for hours.
SanDisk has an excellent SDCX card with 256 GB of storage space which we highly recommend. If you’re a photographer who needs higher capacity, check out this 1 TB card by Lexar.
SD Express
SD Express cards incorporate similar technologies found on your desktop PC or laptop. This format was supposed to mimic NVMe and PCIe Express, which are on your PC.
SD Express was supposed to be a portable solid-state drive, but it just doesn’t work the way it should. It maxes out at a certain speed that doesn’t justify the cost since they can often be up to five times more expensive than similar SD cards.
In short, if you see SD Express cards, you should avoid them. They’re expensive with little to no advancements over standard SD cards.
Micro SD
Micro SD eventually took over SD cards. Phones used to hold bulkier SD cards, but as devices became smaller and data requirements grew, they were replaced with micro SD cards.
These cards are similar to standard SD cards in the way they work. If you’ve ever purchased one, you’ll know they come with an adapter. This adapter is the same size and shape as an SD card.
You can slip the micro SD card into the adapter slot and use it as a standard SD card on your laptop or PC. You can even use these in digital cameras. These are capped at 2 GB, just like standard SD cards.
MicroSDHC
Similarly to SDHC cards, these are Secured Digital High Capacity cards on a smaller scale. They have the same restrictions as SDHC cards, so they only go up to 32 GB of storage.
MicroSDHC cards may be used in gaming consoles such as the Nintendo Switch or your Android phone for enhanced storage. Due to their limit, SDHC cards are incredibly inexpensive, like this one from Hephinov.
MicroSDXC
These cards allow up to 2 TB of space and can fit into a phone memory slot. These also work with SD card adapters to put onto your phone. SDXC cards are used by iPhone photographers and anyone who enjoys taking videos with their phones.
There aren’t many reasons you would need a full 2 TB of space. However, there are plenty of reasons you need more than the 32 GB SDHC cards offer. This 1 TB card from PNY is beyond what most smartphones allow, so it’s best used in drones, cameras and other practical applications.
CompactFlash (CF)
CF cards are uncommon nowadays, but they precede the 1999 SD card by five years. Commonly, you’ll only see CF cards in digital cameras. They don’t have high write speeds compared to SD cards unless you get an expensive one, but they work well with camera-specific equipment.
SD and micro SD card FAQs
Have a few questions about these wonderful little bits of memory that we didn’t answer above? Here are some commonly asked questions about SD cards and micro SD cards to help you.
How do I format an SD card on my Windows PC?
Go to This PC in your Windows settings using a built-in SD card reader or an SD reading device. You’ll find your SD card under Devices and Drives right in front of you. Right-click on your SD card and select the dropdown option labeled Format. Choose your format, tick the box next to Quick Format, and you’re done.
What device can you use an SD or micro SD card in?
You can use them in DSLR cameras, laptops, tablets, smartphones, video game consoles, and even Blu-Ray players. SD cards can also be used in home security cameras to hold onto video footage and more.
Look for SD or micro SD compatibility with any device you purchase. It’s a big selling point, and manufacturers will surely include it in their marketing material.
Keep reading
It’s not just you! Your smartphone might be ruining your memory
We may receive a commission when you buy through our links, but our reporting and recommendations are always independent and objective.