YouTube channel art, 2560x1440

Channel art is uploaded once at 2560x1440 and then shown as four different rectangles. A television shows the full frame. A desktop browser shows a wide strip. A tablet shows less. A phone shows only the centre 1546x423. Those are not resizes, they are crops out of the same upload, which is why a design that fills the full 2560x1440 can look completely empty on a phone.

The layout rule follows from that: everything that matters goes inside the centre 1546x423, and the area outside it carries scene only. That rectangle is roughly 60% of the width and 29% of the height of the upload, which is a much tighter box than it sounds. The channel art in a pack puts the wordmark, the tagline and the invite inside it, with the backdrop extending to the full frame for anyone watching on a TV.

The pack exports that safe area as its own 1546x423 file cut from the full-resolution render, not resized from it. That gives you an exact preview of the phone crop before you upload anything, which is quicker than uploading, checking on a phone and re-cropping.

YouTube shows channel art as a still on every device, so there is no animated version of this format. If you want motion on a channel, the 1280x720 thumbnails from the same pack and the vertical MP4 for Shorts are where it belongs.