How to extract LARGE JPG thumbnail from any youtube video?

Question

YouTube

spoiler

Is it possible to do this through Google Chrome or some other way?

Answer 1

from the jsons feed we get the address 0ajDznH1jdE and insert it into the address of the largest image like i.ytimg.com, now I don’t remember the correct one for the mega size ... they do not change
.. [thumbnails] => Array ( [default] => Array ( [url] => https://i.ytimg.com/vi/0ajDznH1jdE/default.jpg [width] => 120 [height] => 90 ) [medium] => Array ( [url] => https:/ /i.ytimg.com/vi/0ajDznH1jdE/mqdefault.jpg [width] => 320 [height] => 180 ) [high] => Array ( [url] => https://i.ytimg.com/vi /0ajDznH1jdE/hqdefault.jpg [width] => 480 [height] => 360 ) )