YouTube - Mouseover Preview

Uses YouTube's storyboard to show preview images when hovering a video's thumbnail. Hold shift while clicking to jump to the time shown in the preview image.

Installation

You need to have a UserScript extension (e.g. Tampermonkey for Chrome, Greasemonkey for Firefox) installed to run this script.

Install this UserScript

YouTube's inline playback feature interferes with this script. To disable this feature go to Settings > Playback and performance and disable Inline playback.

Credits

These two scripts really helped me find my way around YouTube's storyboard feature:

• youtube-storyboard by bulutcy
• YouTube Storyboard Bookmarklet by Amit Agarwal