Free YouTube Thumbnail Resizer

Most guides give 1280×720 pixels as the size of a YouTube thumbnail. It is a 16:9 picture, the same shape as the video player, so it fills the frame without bars. Several guides also name 640 pixels wide as the smallest size worth uploading.

Some creators work at 1920×1080 and shrink the file afterwards, because a larger master keeps more detail when it is scaled down. Both sizes are 16:9, so either one lines up with the player; the difference is how large the file grows.

These figures come from third-party guides rather than YouTube's own help page, so check YouTube if you need the exact wording of its rules.

A square album cover or a vertical phone picture is the wrong shape for a wide thumbnail. To fit it, you either cut part of the picture away or leave empty space on the sides.

Crop to fill scales the picture until it covers the whole 1280×720 frame, and anything that hangs over the edge is trimmed. You drag and zoom to decide which part stays, so it works well when the subject sits near the middle.

Keep whole shows the entire picture as large as it can be, and fills the bands beside it with a blurred, darkened copy of the same picture. Nothing is lost, which makes it the usual choice for putting a square cover on a wide video.

Guides commonly give 2MB as the largest file YouTube takes for a custom thumbnail. A detailed picture saved as a PNG can pass that easily, while the same picture as a JPG is far smaller.

For these sizes the tool lowers the JPG quality step by step, down to a floor, until the file fits, and then shows you the final size. A PNG cannot be shrunk that way, so if it comes out too large you will see a notice, and switching to JPG usually fixes it.

YouTube also draws the video's length over the bottom-right corner of a thumbnail. Keep faces and text out of that corner; the export still saves the whole picture, so the corner is only a place to leave empty.