Free YouTube Thumbnail Resizer
Turn any image into a perfectly sized YouTube thumbnail — 4K, 1280×720 under 2 MB, Shorts or square — without stretching. Free, no sign-up, nothing uploaded.
Drop an image to see it at 3840×2160
Next step: preview it in the YouTube feed with the free tester.
Thumbnail resizer FAQ
Need a thumbnail worth resizing?
Describe your video and ThumbMagic designs one in the right size from the start — 16:9 up to 4K, with a Shorts version. Your first one is free.