Thumbnail Maker AIYouTube thumbnail size checker and resizer
Upload an image to check it against YouTube's rules (16:9, 640 px minimum, 2 MB from a phone), see the timestamp safe zone, and download a resized JPEG. Runs in your browser.
Choose your thumbnail image
Drop it here or pick it from your phone or computer. It stays on your device.
YouTube wants 16:9, at least 640 pixels wide, as a JPG or PNG. Phone uploads must be under 2 MB (computer uploads allow 50 MB), so 1280x720 under 2 MB works from anywhere.