SD card not showing up? Windows, Mac, Android and camera fixes
You put the card in and nothing happens, or the computer offers to format it. Before you agree to anything, work out where it's getting stuck, because some fixes erase the card.
How far does the card get?
| What you see | Likely cause | Try |
|---|---|---|
| Nothing, not even in Disk Management or Disk Utility | Reader, port or adapter problem, dirty contacts, or a dead card. | Try another reader, a different USB port (not a hub), and the card in a phone or camera. Wipe the gold contacts gently with a dry cloth. |
| Listed in Disk Management with no drive letter | Windows didn't assign a letter. | Right-click the partition, Change Drive Letter and Paths, Add. |
| Shown as Unallocated | No partition, or the partition table is damaged. | If it held files, recover them first. If it's empty, New Simple Volume and choose exFAT. |
| Shown as RAW, or "you need to format the disk" | The file system is damaged, often from pulling the card out mid-write. | Say no to formatting. Recover the files (see below), then format. |
| "The disk is write-protected" | The lock slider on the adapter is down, or the card has failed into read-only mode. | Slide the lock up (towards the contacts). If it stays read-only, copy everything off: many cards lock themselves when they're wearing out. |
| Phone says "SD card unsupported" or "damaged" | Formatted as NTFS, or the file system is corrupted. | Copy files off on a computer, then format in the phone (Settings, Storage) as portable storage. |
| Camera says "card error" or won't record | exFAT card in a camera that only knows FAT32, or a card too slow for 4K. | Format the card in the camera. For 4K video use a card rated V30 or U3. |
| Card shows the wrong size, or files come back broken | A fake card that claims more space than it has. | Test it with a capacity checker such as H2testw (Windows) or f3 (Mac and Linux), and return it if it fails. |
On Windows
- Press Windows+R, type
diskmgmt.msc, press Enter. Look for a disk the size of your card. - No letter: right-click the volume, Change Drive Letter and Paths, Add.
- Has a letter but files look wrong: run
chkdsk E: /fin an admin Command Prompt (use your card's letter). - Not listed at all: check Device Manager for the card reader with a warning sign, and update or reinstall its driver. Laptop built-in readers often need the maker's driver.
On a Mac
- Open Disk Utility, choose View, Show All Devices, and look for the card.
- Greyed out: select it and press Mount. Run First Aid if it won't mount.
- Mounted but not on the desktop: Finder, Settings, and tick External disks for both the desktop and the sidebar.
On Android
- Settings, Storage (or Device care, Storage on Samsung). If the card is listed as unmounted, tap Mount.
- Power off, take the card out, check the tray, put it back, power on.
- Unsupported: back it up on a computer, then use Format in the phone's storage settings.
Get the photos off before you format
Formatting writes a fresh, empty index over the card, so stop using it as soon as it misbehaves. Free recovery tools such as PhotoRec read the raw card and pull out photos and videos even when the file system is unreadable. Recover to a different drive, never back onto the same card. If the card isn't detected at all, software can't help, and only a data recovery service can try. Then put your files somewhere safer: see backing up to an external drive.
Picking a format that works everywhere
exFAT works on Windows, Mac, Android, most cameras and recent TVs, and has no 4 GB file limit. FAT32 is the old option that every device reads, but it can't hold a file over 4 GB, so long videos fail to copy (see file is too large for the destination file system). NTFS is Windows only for writing. Work out how big your videos will be with the video size calculator.
Related
Fake SD card test · SD card locked or write-protected · Card says it needs formatting · SD card full but looks empty · SD card write-protected · USB stick or external drive not showing up · Phone storage full but nothing on it · How much cloud storage you need
Questions
Why is my SD card not showing up on my computer?
Usually the reader or port, dirty contacts, a missing drive letter, or a damaged file system. Open Disk Management (Windows) or Disk Utility (Mac) to see whether the computer detects the card at all, then follow the matching fix.
How do I fix an SD card that says I need to format it?
Don't format yet if you need the files. Recover them with a tool such as PhotoRec to another drive, then format the card as exFAT, or in the camera or phone you use it with.
Why does my SD card say write-protected?
The lock slider on the side of the full-size card or adapter is pushed down. Slide it up towards the contacts. If it still says read-only, the card may have failed into read-only mode, so copy everything off and replace it.
How can I tell if an SD card is fake?
Fake cards report a big size but store only a fraction, so files saved later come back corrupted. Test it with H2testw on Windows or f3 on Mac and Linux, which fill the card and read it back.
Which format should I use for an SD card?
exFAT for cards 64 GB and up and for anything that records long videos. FAT32 only if an old device needs it, keeping in mind it can't store files over 4 GB.
Published · updated .