When watching a YouTube video, if you place the cursor on the loading bar, you can have a preview of the frame of the video at the second where the cursor is placed (see screenshot below). However, this preview is not always available, so how do you enable or disable this feature?

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  • I just had this issue so I checked for different videos. I have noticed that some videos have ads that pop up in the bottom and there are others where an actual video ad plays and then there are some videos without any ads. The preview on seekbar works on videos with no ads and those with video ads. It only didn't work on videos with pop-up style ads. I checked 3 browsers without any additional changes to any software/hardware from one video to another, the results were same across Firefox, Chrome and Edge.
    – Revenheart
    Jan 13, 2019 at 17:48

3 Answers 3


Video thumbnails cannot be disabled by the video uploader. Some videos indeed have no thumbnail but that's a glitch. Note that they can upload their own thumbnails if they want to.

For the viewers, YouTube Nativity has no option to disable video thumbnails, and the two main Google Chrome extensions (viz. YouTube Options and Magic Actions for YouTube) to customize YouTube has no option for it either.

  • Something seems to have changed in recent months (sometime in 2016?). Previously nearly all videos had thumbnail previews. Now almost none do. I can't remember the last time I saw a preview.
    – Simon Elms
    Nov 23, 2016 at 20:23

This is preview of buffer, depending on speed of server it will show instantly or not, but generally it would be shown


I have noticed that the Loss of Preview is gone Due to "Shockwave Flash" , when I disable it on Mozilla Firefox , my Preview feature is back again just like before I added "Shockwave Flash" . So give that a go and see if it works !

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