A YouTube thumbnail is a 16:9 picture. Attach a frame, a photo or a design, crop it to 16:9 where you can see the result, and ToolGPT sizes it to 1280 × 720, 1920 × 1080 or 3840 × 2160.
A screenshot, a photo or a design you made, as JPEG, PNG or WEBP.
ToolGPT draws the 16:9 shape on your picture. Say left, right, top or bottom to choose which part stays.
Ask for the size you want. The thumbnail appears with a download button, ready for YouTube Studio.
At the time of writing, YouTube's help page asks for a 16:9 thumbnail at least 640 pixels wide and suggests 3840 × 2160 for the sharpest result. 1280 × 720 and 1920 × 1080 are common sizes too. It accepts JPG and PNG files, up to 2 MB when you upload from a phone and more from a computer.
Use the largest of those sizes your picture already has. Enlarging a small picture makes it bigger but not sharper, because the extra detail is invented.
A large PNG thumbnail full of gradients can weigh more than 2 MB. Ask ToolGPT to compress it to a size, such as under 2 MB: it writes a JPEG at the best quality that fits, or tells you how close it got. Everything runs in your browser.
Yes. Ask ToolGPT to take a frame from the video at the time you name, then crop and resize that picture.
No. You download it and add it to your video in YouTube Studio.
No. It's cropped and resized in your browser.
Try it with your own file
Open ToolGPT, attach a file, and type what you want done.