Tiny microSD cards power phones, cameras, game handhelds, and dash cams, but the labels are a confusing alphabet soup of numbers and symbols. Buy the wrong one and your device stutters, drops recordings, or runs out of space too soon. Here's how to read the markings and pick the right card.
Capacity: how much it holds
This is the headline number, like 64GB or 256GB. Bigger holds more, but don't just grab the largest one. Make sure your device supports the capacity, since older gadgets may not recognize the biggest cards.
Speed: the part people ignore
Capacity is easy; speed is where buyers get tripped up. The little symbols tell you how fast the card reads and writes, which matters a lot for video and gaming.
- Speed class: A number in a U or a circle indicates minimum write speed.
- UHS rating (U1, U3): Higher is better for high-resolution video.
- Video speed (V30, V60): Look for these if you record 4K.
- A1 or A2: Designed for running apps smoothly on phones and handhelds.
Match the card to the job
A dash cam or 4K camera needs a fast card rated for sustained video. A phone running apps benefits from an A1 or A2 card. For simple photo storage, a basic card is fine.
Avoid the fakes
Counterfeit cards are common on bargain marketplaces. They claim huge capacity but fail fast and lose data. Buy from reputable sellers, and be suspicious of prices that seem too good to be true.
The takeaway
Read past the capacity number. The right speed rating for your device is what keeps your photos, videos, and games running smoothly.