Best SD Card
A secure digital (SD) card is a type of memory card used in a wide range of products, from digital cameras and home surveillance systems to mobile phones. These cards are small and offer non-volatile memory that remains stored even if there's no power being supplied to the card from an external device. As technology has evolved, and more and more data can be stored at a smaller size, these cards have also developed into various sizes, speeds, and memory amounts.
With the right reader or small adapter devices, you can read from just about any SD card on any type of computer. This lets you store impressive amounts of images and data on a tiny card, and transfer it all to another device for viewing or other use. There are quite a few different manufacturers of SD cards, and they offer a wide range of products, so take a look at the SD card buyer’s guide below before making a choice.
Best SD Card for Speed:
When it comes to evaluating SD cards in terms of speed, the most important thing to look at is the "class" of the card as labeled by the manufacturer. These are numerical values, indicated within a small circle, in which higher is better with class 10 is the fastest, with class 8 being slower, down to class 2 which is the slowest. However, high-end cards use the Ultra High Speed standard (UHS) which is shown as a "1" or "3" within a "U" shape. So, you should typically look for SD Cards that are UHS-I or UHS-II models to ensure the fastest speeds possible.
We’ve chosen the following picks for the best SD cards for speed because they’re all UHS-I or UHS-II cards with a speed class of U3 for the best performance possible. The UHS-I models offer read speeds of at least 90MB/s and write speeds of 80MB/s or better, while the UHS-II cards have incredibly fast speeds of 280MB/s when reading and 180MB/s or better while writing data. While the largest option for each model has been chosen, all of these cards offer at least two different storage sizes with maximum storage of at least 64GB.
This a tremendous SD card offering a ton of storage and incredibly fast speeds. Maximum read speeds with this card go up to 300MB/s, which is pretty much as good as it gets. With 128GB of storage, you get plenty of space for pictures and HD video, but there are a couple smaller sizes available if you need less storage. Read Full Review
There’s a lot to like about this SD card, but it just can’t quite match the performance and size of something like the Lexar Pro 2000x. This 64GB model is the largest one offered in this series although there are a couple smaller storage sizes also available. This is a UHS-II U3 speed class card with maximum read speeds of 280MB/s but just not quite as fast as the Lexar model. Read Full Review
While this is certainly an excellent SD card for speed, there’s just a couple options on the market which beat it out in terms of storage size and data rates. This 64GB model is the largest available, though a smaller one is also offered in this series. This is a UHS-II U3 class card with maximum read speeds of 285MB/s and writes speeds up to 180MB/s. Read Full Review
This is a very good UHS-I SD card, so take a look at it if the UHS-II standard doesn't work for you. This model gives you more storage than just about any other choice out there, and many smaller sizes if you want more options. While data transfer speeds on this one can't match a UHS-II card, it's very fast and still offers up to 95MB/s read speeds. Read Full Review
Here is another great option if the UHS-I standard works for your hardware needs, though it certainly cannot compete with UHS-II cards. It has a maximum read speed of 90MB/s, excellent for older SD cards but far short of what is now available. The 256GB of storage gives you a lot of room for your files, and this is a great overall choice if you need a UHS-I card. Read Full Review
Best Micro SD Card:
Many micro SD cards are very similar in terms of storage capacity and transfer rates. At this point, the technology is pretty well standardized, so one card often seems as good as another. However, if you look closer you can find different transfer rates from one card to the next. Some manufacturers also offer nice features or accessories that make these cards easier to use. Since many computers don't have slots for micro SD cards, consider options that include some kind of adapter which let you use the card across various systems. Different card classes can indicate varying levels of performance and speed, so keep that in mind as you’re looking at what different manufacturers have to offer.
We’ve chosen the following best micro SD cards because they offer the best performance and fastest speeds thanks to all of them being speed class UHS-I. You get read speeds of at least 80MB/s with these cards, write speeds of 20MB/s or faster, as well as many different storage options since each of them has three or more sizes available, with maximum amounts of at least 32GB. These picks are all micro SDHC or SDXC cards for optimal speed, but these manufacturers also offer standard SD cards that work with older readers and hardware.
You get tremendous speeds and data rates with this micro SD card, along with quite a few options for different sizes if you need less storage. The UHS-I speed class and 633x design give you read speeds up to 95MB/s which is pretty much as fast as it gets for a micro card. This 128GB model is the largest one available in this series, though there are options down to 16GB if you need less. Read Full Review
This is a very good option in terms of read/write speeds but it’s a bit smaller than some other models on the market. This 64GB card is the largest one available in this series and there are a couple smaller options if you do not need this much storage. It is a UHS-I class card with read speeds up to 95MB/s, so if 64GB of storage is sufficient for you, then it is a great choice. Read Full Review
While there’s a lot to like about this micro SD card, the storage size is just a bit too limited compared to some other models on the market. This 32GB card is the largest option within the series, so if you need 64GB or 128GB of storage, then this is definitely not the right choice. However, read/write speeds with this card are excellent up to 90MB/s. Read Full Review
This is certainly one of the most visually appealing micro SD cards on the market, and if you tend to use multiple cards, then it’s a great option. There are plenty of storage sizes available for these cards, as well as packages which include adapters if you need one. Data rates with this card are decent with maximum read speeds of up to 80MB/s and write speeds up to just 20MB/s. Read Full Review
This is a UHS-I class card with maximum read speeds of 90MB/s and write rates up to 80MB/s, which gives you great overall performance. While there are a couple smaller storage sizes available within this series, they only go down to 32GB, which still may be too much for some devices. Read Full Review
Best SDHC Memory Card:
When looking at different SDHC memory cards, you should typically look at more than just their storage capacities. All of these cards are designed to hold more data than a standard SD card, and while you might look at 32GB models specifically to compare against each other, you can find other sizes for many of these products. After determining the storage size you need, look at things like transfer speeds, product durability, and overall quality based on your own experience and reviews from others. All of these models should work quite well for a camera or other common application for an SDHC card.
We’ve chosen these picks as the best SDHC memory cards because they offer a maximum capacity of 32GB which gives you plenty of space for pictures and other files. You can get at least two different sizes with each of these models in case 32GB is more than you really need, though many of them have three different capacities to choose from. Transfer rates with these cards are excellent, since they are speed class 4 or better models, with maximum read speeds of at least 45MB/s and write speeds of 4MB/s or better.
If speed is the most important factor to you in looking at different SDHC cards on the market, then this is the one to choose. It’s a UHS-I class card with maximum read speeds up to 90MB/s which is pretty much as fast as it gets for this type of card. There are 16GB and 8GB models available if you need less storage, as well as larger SDXC cards within this series. Read Full Review
This pick is almost everything you could want in an SDHC memory card, giving you 32GB of memory and options for 16GB or 8GB models if you need less storage. This is a UHS-I speed class card that gives you 45MB/s read speeds and up to 20MB/s write speeds. Read Full Review
This is a great card overall that offers a lot of different storage sizes and great read/write speeds. There may be some cards on the market that are slightly faster, but this model is definitely one of the fastest, with read speeds up to 80MB/s. There are also 16GB and 8GB models available within this series, as well as larger options that use the SDXC format. Read Full Review
This card from Kingston is excellent, though it does have a few limitations to keep in mind. Its speed and performance are tough to beat which delivers UHS-I speed and read rates up to 90MB/s and write speeds up to 45MB/s. There’s a 16GB model available if you need a different size, as well as many larger options, though those are SDXC cards. Read Full Review
While this is certainly an excellent SDHC memory card in many ways, it just isn't as good overall as some of the other models on the market. It has decent transfer rates, but it’s a speed class 4 card, which means write speeds could be as low as 4MB/s. There are a couple smaller sizes available of this card if you need less storage, though no larger ones in this series. Read Full Review
SD Card Buyer's Guide
Choosing the right SD card may seem simple enough, but there are actually quite a few factors you should consider to ensure you get the right card for your needs. There are different types and physical sizes available, and each one has its own strengths and weaknesses.
You should look at the maximum capacity and speed class to ensure a card which can hold all of your data and transfer it to and from other devices as quickly as possible. The actual read/write speeds and even wireless functionality are also worth considering before making a final choice and picking a card from a reliable manufacturer.
Types of SD Cards
There are different physical sizes and a couple storage variants to consider as you look at different SD cards, and the right choice ultimately depends your preferences and devices.
The original design and still one of the most popular sizes, standard SD cards are commonly found in consumer-targeted digital cameras (professional cameras often use CompactFlash instead). They have excellent speeds and capacities available and are a great choice for general use. While you can use a smaller card in devices designed for SD cards via an adapter, if your device can use an SD card, you should pick an SD card.
The next most common design is smaller than the standard model but still offers excellent capacity and speed. This is the size most commonly found in smart phones and similar devices. You should pick a MicroSD card for any device designed to use it, and you can pick up an adapter to make it fit into a computer or reader with a standard SD card slot.
This option is very rarely used and its size is just between the standard card and MicroSD. While it offers speeds and capacities comparable to the standard card, there just is not much use for this size due to a lack of devices designed for it. There is simply no reason to choose this card unless you have a device specifically intended for a MiniSD card.
This is a variant that you can typically find as either an SDHC or MicroSDHC card. Standard SD Cards only have up to 2GB of storage, so anything with more than that is a high-capacity model. If you want as much storage as possible on your card, then look for this option rather than a standard card.
Here is another storage variant if you need even more space than a SDHC card. You can find this labeled as either SDXC or MicroSDXC and this standard goes beyond 32GB of storage, the limit on HC models. If you need 64GB or more of storage, then XC is the way to go.
In looking at maximum capacity, you have to consider the type of SD card you choose, which has a tremendous impact on storage size. In general, standard SD cards can have up to 2GB of data on them. SDHC cards can store between 4GB and 32GB of data, while SDXC cards have a maximum capacity between 64GB and 128GB of storage, though there is the potential for future XC cards to have up to 2TB of data.
Most cards have their capacity printed directly on them, so simply looking at the card should reveal how much data it can store. Keep in mind that photographs and video take up a lot more storage than text or simple documents, so choose a large capacity option, at least 32GB, for a digital camera or if you like to take pictures with your phone.
The speed class is a simple indication of how quickly data transfers to and from the card. While the specific read and write rates give you more detailed indicators, you can use the speed class to get a good general sense of how fast the SD card transfers data. Classes are indicated numerically, starting at 2, then 4, 8, and finally 10.
Higher numbers indicate faster speeds, but keep in mind that there is also a designation for Ultra High Speed (UHS) starting over at 1. For standard picture taking, a speed class of 4 or 8 should be sufficient, while class 8 is best for video. If you want to capture HD images and video, however, choose an SD card with a speed class of 10 or UHS-1 to ensure the best quality possible.
Read and Write Speeds
While speed class is a good general guideline when choosing an SD card, you should also look at the specific data rates for a better sense of how information will transfer to and from the card. Of the two numbers, read speed is somewhat less important since it refers to how quickly you can access data on the card.
You don’t want to wait forever for your images or documents to transfer from the card to a device or computer, write speed is vital since it indicates how quickly data is written to the card. When using an SD card in a camera, for example, write speed controls how quickly you can snap images and is very important for HD video. Look for a write speed of at least 10MBps to 15MBps, while you want 40MBps to 45MBps for high quality HD pictures and video.
This is very rare in SD cards, but something still worth considering and looking at. Most SD cards work quite simply by inserting them into a device, reader, or card slot on a computer and then accessing the data. There are some cards, however, that include wireless functionality, allowing you to access the data on them through a wireless network or device.
Other factors like speed and storage capacity are definitely more important, but if you have a setup that could really benefit from accessing data on your SD card wirelessly, then look for a model that includes this functionality.
SD cards are small, plastic storage devices that can include a lot of important data. In order to protect that information, look for models that are designed with durability in mind. You can find cards that have high capacity and fast data speeds and are waterproof, shock resistant, and dust proof. Some cards also include error correction functionality that helps detect any errors and correct them automatically, to protect you from data corruption.
Manufacturer and Warranty
Due to the inexpensive nature of SD cards, there are many different manufacturers out there who make a variety of models to choose from. When looking at different cards, make sure you pick a reliable manufacturer such as Kingston, SanDisk, or Transcend. Other companies like HP, Verbatim, and Lexar also make excellent SD cards. Most of these companies actually offer lifetime warranties on their SD cards, so you know they are built to last, even if they are inexpensive.