SD card or USB stick says full but looks empty? Hidden files, the Mac Trash, and smaller-than-expected cards
You deleted everything, the card looks empty, and the camera, phone or computer still says it's full. The space is almost always still there, just hidden or cut off.
Where the space went
| What you see | Why | Fix |
|---|---|---|
| Deleted on a Mac, card still full | Deleted files move to a hidden .Trashes folder on the card itself. | With the card plugged in, empty the Bin. Then eject. |
| Phone says the card is full, file app shows little | Hidden thumbnails, app caches, or a LOST.DIR folder of rescued file pieces. | Show hidden files on a computer and check those folders, or back up and format in the phone. |
| Camera says full, computer shows photos you already copied | Copying doesn't delete. The photos are still on the card. | Once you've checked the copy, delete them or format the card in the camera. |
| Card shows a tiny size, like 256 MB on a 32 GB card | Only one small partition is visible, often from a Raspberry Pi image or a device that made its own. | Reformat the whole card (below). |
| 64 GB card shows about 59.6 GB | Labels use 1 GB = 1,000,000,000 bytes, computers often count 1,073,741,824. Nothing is missing. | Nothing to fix. See the unit converter. |
| Thousands of tiny files use far more than their size | Each file takes at least one whole block, and big cards use big blocks. | Zip them into one file, or accept it. |
| Files corrupt after a certain amount, or a huge card was suspiciously cheap | A fake card that reports more space than it really has. | Test it with H2testw (Windows) or F3 (Mac, Linux). A fake can't be fixed, only returned. |
See the hidden files
- Mac: open the card in Finder and press Cmd+Shift+. (full stop) to show hidden items. Press it again to hide them.
- Windows 11: File Explorer, View, Show, Hidden items. System Volume Information is Windows' own folder and is normally small.
- Android: in Files, the menu often has "Show hidden files". Folders starting with a dot, like .thumbnails, are hidden ones.
Get a card's full size back
Formatting erases everything, so copy anything you want off first.
- The easiest route is the free SD Memory Card Formatter from the SD Association, for Windows and Mac. It rewrites the card's layout the way the SD standard expects, which also fixes shrunken partitions.
- On a Mac without it: Disk Utility, View, Show All Devices, select the card itself (the top line), Erase, Format ExFAT (or MS-DOS FAT for cards of 32 GB or less), Scheme Master Boot Record.
- On Windows, if Explorer won't offer the full size, Disk Management can delete the old partitions and create one new one. Double-check you've selected the card, not your main drive.
- For a camera, finish by formatting the card in the camera itself, which sets it up exactly how the camera likes.
Related
Files vanish or corrupt? Test for a fake card · Which format for a card or stick · SD card not showing up · Phone storage full but nothing on it · File too large for the destination file system (FAT32) · Drive or SD card write-protected · What is exFAT? (Wirebook)
Questions
Why is my SD card still full after I deleted everything?
If you deleted on a Mac, the files are in a hidden .Trashes folder on the card until you empty the Bin with the card plugged in. Otherwise check hidden folders like thumbnails and LOST.DIR.
Why does my 64 GB SD card only show 59 GB?
Card makers count 1 GB as 1,000,000,000 bytes, while computers often count 1,073,741,824. 64 billion bytes is about 59.6 of those, so nothing is missing.
My SD card only shows a few hundred MB. How do I get the full size back?
It has a small partition left by a Raspberry Pi or another device. Back up anything on it and reformat the whole card, for example with the SD Association's free SD Memory Card Formatter.
What is the LOST.DIR folder on my SD card?
Android puts pieces of files there that it rescued after the card was removed or the phone shut off mid-write. If you don't recognise anything in it, it's safe to delete.
How can I tell if my SD card is fake?
Run a full write-and-read test with H2testw on Windows or F3 on Mac and Linux. A fake card fails once you go past its real capacity.
Published · updated .