Options - Preview

Display file info below the thumbnail

File name, file size, image size in pixel, date modified, and displayed size.

A woman with two mouths, eating cakes (1841)

Enable for network files

Display preview of files over network.

Enable for files in compressed folder

Currently supports zip and cab files.

Show only with Shift key down

If unchecked, Shift key prevents preview and ordinary tooltip is displayed.

Display even if folder window is not active

Displays preview of file in inactive window by mouse cursor.

Try to obtain EXIF thumbnail

Will be faster when the image file is extremely large, though thumbnail is fixed in size and lower quality.

Save playback points of movies and musics

If unchecked, preview starts always in the beginning of file.

Show at the corner of screen

Always displays preview window at the right-bottom corner of screen.

Try to show in full size

Ignores size settings and tries to show in maximum size that screen allows.

Try to show in specified max size

Displays in size specified in user setting even if smaller than that.

Use hardware acceleration if available

Uses hardware acceleration when playing videos.

Slideshow in full screen

While showing picture preview in full screen, automatically displays next file in folder at specified intervals.
Preview shortcut keys works while slideshow. For example, Num 5 is "Pause/Resume". See Preview Key Map.

First delay to show preview

Specify delay before preview is displayed by mouse hover and change of selection in view or menu.

Maximum memory size used by image cache

Limits memory usage in rough estimate.

Clear image cache

Clear cache immediately.

File extensions

You can specify file extensions that QTTabBar tries to display preview.
Before you are pressing "+" button to add an extension, you have to select which type of preview the extension has among Picture (still image), Movie and Music (playable), and Text.

Size of Preview window

You can specify max window sizes.

Text Max Read in KiB

Reading size from the beginning of text file.
You can scroll Text preview when overflowed, by NumPad4 and NumPad6 key (default).