This site is a free online media application that allows you to view or download any YouTube thumbnail preview image. The current formats supported by this application are - YouTube (HD, HQ, 1080p, 4K). Thumbnail Save is a free and faster platform to grab any YouTube thumbnail on any device. You can save the desired thumbnail on your computer, cell phone, PSP, iPhone or nearly almost every device.
How Steps to view and save a YouTube thumbnail preview image: