What is a THUMBDATA file? A THUMBDATA file is a cache file created by some Android devices' Gallery app. It contains indexed property information about every thumbnail image shown in your Gallery. Caching this information helps Gallery load thumbnails more quickly.

More Information THUMBDATA files are hidden files, which are stored in Android devices' hidden .THUMBNAILS folders. As such, you can access your device's THUMBDATA files only if you have access to hidden Android files. The files' extensions typically end with a number followed by one or two dashes and an additional long string of numbers. For example, a THUMBDATA file may be named .THUMBDATA3--1967290299 . Can I delete THUMBDATA files? If a THUMBDATA file is taking up too much space on your Android device, you can safely delete the file. The next time you open the Gallery app, it will automatically create a new THUMBDATA file, which will contain indexed property information for only the images currently stored on your device. If you've recently deleted images from your device, this will reduce the size of your THUMBDATA file. If you want to stop your device from creating THUMBDATA files altogether, you can: Find your current THUMBDATA file. Note the file's name. Delete the file. Create a new text file in the same directory. Give the file the same name as the THUMBDATA file you just deleted. This will stop your Gallery app from creating a new THUMBDATA file. Note that Gallery may load thumbnails more slowly if you prevent it from creating a THUMBDATA file.