YouTube
A thumbnail competes in a grid. Consistency across a series is worth more than detail in any one of them.
For YouTube · 1280×720
Shown at the real ratio with the Drift Night Anime design. Hover to animate. Previews are watermarked.
A thumbnail is a 1280x720 image under 2MB, and it is almost never looked at on its own. It is looked at in a grid of twelve other thumbnails, at maybe 320 pixels wide, by somebody scrolling. That is the design brief: one readable thing, strong contrast, and nothing fine.
The 1280x720 in a pack is a base plate rather than a finished thumbnail. It carries the scene and your server name composed at 16:9, with clear space where your own episode text goes and the bottom right corner kept empty for the duration badge YouTube stamps on every thumbnail. Dropping your episode title onto it in any editor takes a minute and the whole series then shares one identity, which is the thing that actually builds a channel.
The same file works as a store capsule. A 1280x720 at 16:9 is close enough to what most store fronts and listing sites want for a header card, and because it is a still at full resolution it downscales cleanly to whatever a particular site asks for.
No animated version exists for this format, because YouTube thumbnails are still images and always have been. Animated preview behaviour on YouTube comes from the video itself, not from the thumbnail file.
A thumbnail competes in a grid at a few hundred pixels, so high contrast and one clear subject win.
Drift Night rendered as anime artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.
Drift Night rendered as grunge artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.
Drift Night rendered as painted artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.
Drift Night rendered as photoreal artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.
Supercar Garage rendered as anime artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.
Supercar Garage rendered as grunge artwork, with live motion, drifting particles and a chromed wordmark. Every format in the catalogue, still and animated.