SD memory cards are the unsung heroes of the gadget age. They power digital cameras so that we have room for thousands of pictures. They expand storage on smartphones and tablets so we don't have to worry about running out of built-in space. If you own a device that stores data of any kind, you can bet that an SD memory card is involved.
While all SD memory cards pretty much look the same, there are some key differences. To get the best value, it's important to know what to look for as well as the memory card requirements for your devices. This guide also includes our picks for the best SD memory cards on the market. An SDXC memory card by Sony is our best of the best due to its incredibly fast transfer speed and large storage capacity.
Considerations when choosing SD memory cards
To find the right SD memory card, start by considering these questions.
How much storage do you need?
Capacity is the most important feature of SD memory cards. Memory cards come in all different sizes, although the most common capacities are 16GB, 32GB, 64GB, and 128GB. Before you start shopping, take some time to think about how much space you need. Start by checking your devices to see how much memory they require and if they have any capacity limits.
What type of SD memory card does your device use?
There are three different kinds of SD memory cards: secure digital (SD), secure digital high-capacity (SDHC), and secure digital extended-capacity (SDXC). Each is faster than the last and can support a larger capacity. Before you start shopping, check the device that needs the memory card and see which type it takes.
How many SD memory cards do you need?
Most SD memory card manufacturers offer bulk discounts, so it can save you money to buy in batches.
There are many different specifications to compare between memory cards, but these are the features to focus on.
When it comes to SD memory cards, the brand matters. No-name brands often produce sub-par hardware. Stick with the big names in the industry: SanDisk, Lexar, Sony, Transcend, PNY, Verbatim, Kingston, and Samsung. Don't get wooed by low prices from other brands.
Every SD memory card has a series of ratings for how it performs. For example, each card is assigned a class that indicates its overall speed. We recommend sticking with cards that are class 10 or better.
SD memory cards have two speed ratings: how fast they can write data (like when you take a picture) and how fast they can transfer data when connected to your device. Look for SD cards with write speeds and transfer speeds of at least 80MB/s.
Q. What's the largest SD memory card I can buy?
A. As of this writing, the highest-capacity memory cards have a whopping 1TB of storage (that's 1,024GB). Storage capacities are always increasing as technology evolves, so expect even larger versions in the future. Keep in mind that higher-capacity drives are always more expensive.
Q. Can I use the same SD memory card with different devices?
A. Yes, but you may need to reformat the card first. There's no guaranteeing that two devices will use the same formatting. If you want to reuse a memory card on a new device, make sure you've transferred the contents before making the switch. Otherwise, your content from the first device could get permanently deleted.
Q. How do I keep my SD memory card safe from damage?
A. If you're planning on storing your SD memory card outside of your device, we recommend getting a carrying case. Memory cards can scratch easily, so it's best to protect the exposed metal parts at all times. Keep your SD memory cards somewhere that won't get too hot or cold--extreme temperatures can also cause severe damage.
SD memory cards we recommend
Best of the best: Sony High-Performance SDXC Memory Card
Our take: Sony's SDXC memory card is built for professionals, so it's incredibly fast, durable, and capacious. A no-compromises SD memory card.
What we like: It's got 300MB/s read and write speeds, so it's as fast for taking pictures as it is for transferring them to your computer.
What we dislike: The included software for recovering accidentally deleted files is not great. Compared to other memory cards, this one is pricey.
Best bang for your buck: SanDisk Ultra SDXC Memory Card
Our take: SanDisk memory cards are a good, reliable option. They're not the fastest by a long shot, but they're durable and are priced well below the competition.
What we like: The price. For a class-10 memory card, this is an absolute steal. SanDisk cards rarely if ever fail, so the peace of mind goes a long way.
What we dislike: It's 80MB/s speed is just so-so. It can keep up with a 1080p video camera, but if you're planning on recording anything in 4K, you're going to need a faster card.
Choice 3: Lexar Professional SDHC Memory Card
Our take: Lexar memory cards offer a good balance between cost and value. If you're looking for an affordable SD memory card that can keep up with most devices, this is a solid option.
What we like: The 95MB/s transfer speed is great for quickly transferring content. The price is excellent, and you can get a discount by ordering in packs of two.
What we dislike: While the transfer speed is moderately fast, this card's 20MB/s write speed is definitely on the slow side.
Jaime Vazquez is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.
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