YouTube generates thumbnails in five standard sizes for every video. Understanding which size to use depends on your intended application.

The Five YouTube Thumbnail Resolutions

NameFilenameSizeUse Case
Defaultdefault.jpg120×90Tiny previews
Mediummqdefault.jpg320×180Email, sidebar
Highhqdefault.jpg480×360Blogs, presentations
Standardsddefault.jpg640×480Web content
Max Resmaxresdefault.jpg1280×720Print, HD displays

Which Thumbnail Does YouTube Use?

YouTube uses the maxresdefault thumbnail for the video page if it exists. For older videos or those uploaded before HD was common, only hqdefault may be available.

Aspect Ratio Note

The default, medium, and standard thumbnails use a 4:3 aspect ratio, while high and maxres use 16:9 (widescreen). Modern YouTube videos are almost always 16:9.