Does anyone know how to turn off the large thumbnails on YouTube?

If I sign-in, the thumbnails go from a good normal size to huge.

Reddit threads about this nuisance yield no answers. Stack Exchange is my only hope!

2 Answers 2


This may be an experiment YouTube is doing, to see whether or not people engage with the site more if the thumbnails are larger. There sometimes are workarounds for this, though unfortunately YouTube doesn't have any easy opt-out feature. You can try some of these however:

  • Clear cookies. Often, these experiments are cookie-based (with the VISITOR_INFO1_LIVE cookie being the main culprit), though yours might be account-based instead.
  • Use the old design. You can switch to it with the disable_polymer URL parameter, or using an extension/userstyle to emulate it.
  • Use a userstyle. There are quite a few available, though they tend to break whenever YouTube updates something (like they did with your thumbnails). Knowing a bit of CSS to fix things yourself helps here.
  • Use a different browser and/or resize the browser. This will definitely have a different cookie set, plus even account-based experiments sometimes are set out to work in one browser only (which usually is Chrome), or on only one type of screen size or aspect ratio.
  • Disable polymer worked! Thank you! Oct 6, 2019 at 13:11
  • Note: deleting cookies did nothing Oct 6, 2019 at 13:19

As Leo Wattenberg wrote, there are several ways to undo the changes.

I just reverted them as well as I could with some CSS and published it here as a userstyle: https://userstyles.org/styles/176683/berny23-s-youtube-enhancements

(You can use Stylish or any other userstyles/css addon for Firefox, Chrome, etc.)

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