YouTube Thumbnails Downloader is a program that downloads all thumbnails of all videos on the channel you select. All you have to do is enter the channel link into the program, it will calculate the number of videos and download all the thumbnails to it. Sometimes problems may arise because of the API key, and to solve this problem, you only need to visit a site Google API To get the key of the above counters and put the key in the assigned field. If you encounter a problem that cannot be solved, do not hesitate to contact me via WhatsApp or Instagram.