After a new round of testing, the Lexar Professional 1800x v60 UHS-II SDXC is our pick for the best SD card for most people. The SanDisk Extreme V30 UHS-I (128 GB) is best for less demanding tasks.

To find out why, we need to take a look under the hood at how SD cards deal with storage capacity. A rare 4 GB card produced piror to the ratification of SDHC. Compatibility of such cards is ...