YouTube channel art is seen on TVs, desktops and phones, and each crops it differently. The maker creates 2560×1440 channel art, a 1280×720 thumbnail and a square for community posts in one consistent style.
YouTube formats in the maker: channel art 2560×1440, thumbnail 1280×720, post 1080×1080. Tick the ones you need and choose how many picture variants to make for each, from one to four.
Everything important in channel art has to fit the central 1546×423 safe area, and that's exactly where the maker places your text and logo. For clickable thumbnails with your face and a big headline, also try the Covers tool.
Pictures are drawn by GPT Image 2.5, Nano Banana, Seedream or FLUX; you pick the model before you start. For shapes the main picture doesn't have, the AI extends its edges, so nothing important gets cropped.