Best SD Cards for Cameras and Phones

A slow SD card can't keep up with a camera recording video, causing dropped frames or a shutdown. The speed class printed on the card tells you whether it's up to the job.

Read the speed class

The class rating on an SD card indicates its minimum write speed. For 4K video, look for a U3 or V30 card. For 1080p, U1 or V10 is usually enough. The faster the video, the higher the class you need.

What to look for

• A U3 or V30 card for 4K video
• Enough capacity for your shooting sessions
• A reputable brand, since cheap cards fail and corrupt data

Why brands matter

Counterfeit and no-name cards often misreport their speed and fail unexpectedly, corrupting photos and videos. A genuine card from a known brand is worth the small premium, especially for irreplaceable footage.

Buy a U3 or V30 card from a reputable brand for 4K video, or U1 for 1080p. The right card prevents the corrupted files and dropped frames that cheap cards cause.