Let's get to the point immediately, here is the sample YouTube video URL
https://www.youtube.com/watch?v=yT8Y8_uwk0k
In the above URL after "v=" is the ID of a video
yT8Y8_uwk0k
To view the YouTube video thumbnail replace the video ID in the link below.
👉 https://img.youtube.com/vi/yT8Y8_uwk0k/maxresdefault.jpg
There is another direct way to view and save the youtube video thumbnail given below, just paste the video link and view or save.
Read More: How to create youtube thumbnails online