Back up any important files on the SD card
Insert the SD card into your computer
Open File Explorer (Windows) or Finder (macOS)
Confirm the correct drive letter/name for the SD card
Windows: Right-click the SD card drive → Format
macOS: Open Disk Utility → select the SD card in the left sidebar
Windows: Choose the file system
macOS: Choose the format (MS-DOS (FAT) / exFAT / APFS as applicable)
Windows: Set Allocation unit size to Default (if shown)
macOS: Choose the format and scheme (if prompted)
Windows: Check Quick Format (optional)
Windows: Click Start → confirm the warning
macOS: Click Erase → confirm the action
Wait for the format to complete
Eject safely
Windows: Right-click the SD card → Eject
macOS: In Finder or Disk Utility, eject the SD card
Remove the SD card after the status shows it’s safe to remove