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What Is Thumbs.db, Can You Delete It, and What Is Still Inside

Thumbs.db is a cache of small preview images that Windows Explorer builds when a folder is shown in thumbnail view. It is not one of your files, it is safe to delete, and it holds thumbnails of pictures that may no longer exist.

.db
Open it on this site

Why it will not open

  • It is not a document. Double-clicking asks which app to use because no app is meant to open it; Explorer reads it directly when drawing icons.
  • It is a container, not a picture. Inside is a small database (the same compound-file format as .doc and .msg) with one thumbnail per image the folder once held. Image viewers do not know how to look inside.
  • It reappears. Delete it and Explorer recreates it the next time the folder is shown in a thumbnail view — on network shares and removable drives, where Windows still uses this format.

How to open it

See what is inside before deleting

  1. 1 Make hidden files visible (Explorer → View → Hidden items). Thumbs.db is always hidden.
  2. 2 Drop the file into the Thumbs.db viewer on this site. It lists every thumbnail with the original file name and date Explorer recorded.
  3. 3 Save any thumbnail you want to keep — individually or as a ZIP. Then delete the file.

When Windows says it is in use

  1. 1 Explorer has the file open because it is showing that folder. Switch the folder to Details view, or close that Explorer window.
  2. 2 Delete again. If it still refuses, move Thumbs.db to a different folder and delete it there, or delete after restarting.

Stop Windows creating it

  1. 1 On Windows 10/11 Pro, open gpedit.msc → User Configuration → Administrative Templates → Windows Components → File Explorer, and enable "Turn off the caching of thumbnails in hidden thumbs.db files".
  2. 2 On Home editions, create the DWORD value DisableThumbsDBOnNetworkFolders = 1 under HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\Explorer.
  3. 3 Existing files are not removed by the setting; delete them once and they will not come back.

Why it matters for privacy

The thumbnails stay after the originals are deleted or moved. A Thumbs.db in a folder you hand over — on a USB stick, in a ZIP, on a shared drive — can show pictures you believed were gone. Check it, then delete it, before passing the folder on.

Thumbs.db versus thumbcache_*.db

Since Windows Vista, local folders use thumbcache_*.db files in the user profile (a different format). Thumbs.db is still created on network folders and removable drives, which is why it keeps turning up on office file servers.

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Frequently Asked Questions

Is Thumbs.db a virus?
No. It is created by Windows Explorer itself. Its size grows with the number of pictures in the folder, which can look suspicious, but it is only a cache.
Will deleting Thumbs.db delete my photos?
No. The photos are separate files. Thumbs.db holds only small copies used to draw thumbnails, and Explorer rebuilds it if needed.
Can I recover a deleted photo from Thumbs.db?
Only its thumbnail — typically 96×96 or 256×256 pixels. It is enough to see what the picture was, not to print or use it. The viewer on this site extracts them.
Why is there a Thumbs.db in a folder that has no pictures?
The pictures were there once and have since been deleted or moved. The cache was not. That is exactly the case the viewer is for.