What setting should be made in the script settings such that when I move the mouse pointer over a YouTube video thumbnail picture and then click on the "Ctrl" key, the thumbnail picture image should maximize in it's full resolution?

I click on Configure > Find Rule > Youtube (Preview Image) and then apply that.

However, the image does not show. I have provided a screenshot of my current settings for reference.

Works for me in my tests on youtube.com. Where do you test it?

Works for me in my tests on youtube.com. Where do you test it?

Example page where I am checking:

https://www.youtube.com/@DarkSynthAmbient/streams

I was experimenting with the settings and I somehow managed to show the thumbnail image but the issue is that it does not maximize to the full resolution. (see screenshot). Can you please provide the rule so that the image popsout to the full resolution?

This is the maximum provided by youtube.

Yt provides a maximum of 1280x720 resolution for the thumbnail image. You can easily check this by visiting this page

https://youtube-thumbnail-grabber.com/

and then Pasting any youtube video link (Ex: https://www.youtube.com/watch?v=-WpJ0Igqfkc)

The direct link to the full resolution image is : https://img.youtube.com/vi/-WpJ0Igqfkc/maxresdefault.jpg

I didn't know that, the rule is submitted by someone else. Try using the URL you've shown in the rule i.e. replace 0.jpg with maxresdefault.jpg.

Done that but no luck. I still see the smaller image being popped out. Can you please check?

Works for me.

{"u": "||youtu", "r":"(youtu\\.be/|youtube\\.(googleapis\\.)?com/(watch.+?v=|v/))([a-z0-9_-]+)","s": ["https://img.youtube.com/vi/$4/maxresdefault.jpg","https://img.youtube.com/vi/$4/0.jpg"]}

Thanks for the rule. I observed it works now perfectly when I hover the mouse over the title of the video and then press the "Ctrl" key. For some videos, when I hover the mouse over the thumbnail image and then click on the "Ctrl" key, it just pops out the smaller image. But that's fine. It works now. Thanks for all your hep on this.