How to stop Nautilus from creating thumbnails of specific file types?

Thumbnails of specific file types can be disabled using dconf editor.

Install dconf editor:

Hit Alt+Ctrl+T and run the following command:

sudo apt-get install dconf-tools

Or search for "dconf-tools" in Software Center and install it from there.

How to disable thumbnails of specific file type?

• Once installed, Hit super key (windows key) to open Unity dash and search for "dconf editor" and open it.

• Navigate to org > gnome > desktop > thumbnailers

• Paste the MIME type of PDF 'application/pdf' in the value field of disable key, Like shown below.

This will prevent Nautilus from generating thumbnails of PDF's in the future but old thumbnails will be there. To solve this you'll have to clear Nautilus thumbnail cache.

• Open your home directory and Hit Ctrl+H to show the hidden files and folders.

• Open .thumbnails and delete all the files in it. Edit for 19.10: Open .cache and delete the thumbnails folder.

• Restart your system or kill Nautilus (alt+f2; nautilus -q) for change to take effect.

To disable thumbnails for other file types, Add there MIME type in disable list as described above. Seprate multiple types with comma. like this:

['application/pdf','image/jpeg','video/mp4']

For complete list of MIME types visit iana.org.

In order to stop showing thumbnails for any video file (because on my little HTPC it's causing high CPU usage):

First, clean the thumbnail cache:

rm -rf ~/.cache/thumbnails

Apply the mime type list:

gsettings set org.gnome.desktop.thumbnailers disable "['application/annodex','application/mp4','application/ogg','application/vnd.rn-realmedia','application/x-matroska','video/3gpp','video/3gpp2','video/annodex','video/divx','video/flv','video/h264','video/mp4','video/mp4v-es','video/mpeg','video/mpeg-2','video/mpeg4','video/ogg','video/ogm','video/quicktime','video/ty','video/vdo','video/vivo','video/vnd.rn-realvideo','video/vnd.vivo','video/webm','video/x-bin','video/x-cdg','video/x-divx','video/x-dv','video/x-flv','video/x-la-asf','video/x-m4v','video/x-matroska','video/x-motion-jpeg','video/x-ms-asf','video/x-ms-dvr','video/x-ms-wm','video/x-ms-wmv','video/x-msvideo','video/x-sgi-movie','video/x-tivo','video/avi','video/x-ms-asx','video/x-ms-wvx','video/x-ms-wmx']"

Then, just in case:

nautilus -q

I have got the mime type list from here.