Why preview at feed size?
You design a thumbnail at 1280×720 on a big screen — but most viewers meet it at ~120–360px wide, squeezed between twenty competitors. Text that reads beautifully in your editor becomes soup at feed size. This tool renders your image at the three sizes YouTube actually uses, on dark and light UI, with a blur toggle that simulates a scrolling glance.
The three rules of tap-worthy thumbnails
One subject. A face or object with clear emotion beats a collage. Three words max. If the text needs reading, it's a caption, not a thumbnail. Contrast is reach. Feeds are busy — brightness and color separation decide whether you exist.
FAQ
Are my images uploaded anywhere?
No. The previews are rendered entirely in your browser with the FileReader API — nothing is sent to our server or anyone else's.
What size should a YouTube thumbnail be?
1280×720 (16:9), under 2MB, JPG/PNG/WebP. The tool warns you automatically if your file breaks any of those rules.
Can you make thumbnails for me?
Every Studio delivery includes three generated thumbnail options tested at feed size — along with the finished video, titles, description and tags.