YouTube rejects thumbnails over 2 MB and stretches anything that isn't 16:9. This preset crops your image to exactly 1280×720 and fits it under the cap at the best quality — one drop, one download, ready to upload in YouTube Studio.
How it works
- Check the target. This page is preset for the spec above — adjust any number to match your exact form.
- Drop your photo. ExactKB finds the best quality and dimensions that land inside the size window — including padding files up when a form has a minimum size.
- Download. The file fits the requirement on the first try.
FAQ
JPG or PNG for thumbnails?
Both work. JPG is smaller; PNG is better for text-heavy thumbnails with flat colors. Switch the output format above if you prefer PNG.
Is my photo uploaded to a server?
No. ExactKB runs entirely in your browser. Your file never leaves your device — this page even works offline.