SOCIAL SIZE
☞ runs entirely in your browser — nothing is uploadedDrop your image here
or click to browse — JPG, PNG, WebP
Crop preview
OneImageTool
Free Image Tools
SOCIAL SIZE
1280 × 720, cropped and exported at the exact size YouTube wants.
or click to browse — JPG, PNG, WebP
Crop preview
1280 × 720
YouTube asks for 1280 × 720 and refuses anything under 640 pixels wide, but the number that should drive your design is the one nobody quotes: in a sidebar or a phone feed, that thumbnail is drawn about 168 pixels across. Everything is displayed at roughly an eighth of the size you are editing it at. Text that looks readable at full size becomes a grey smudge, which is why thumbnails that work use three or four enormous words and one clear subject.
The mechanics are simple and worth getting right anyway. The crop box here is locked to 16:9, so whatever you frame keeps the shape YouTube expects; on export it is resized to exactly 1280 × 720, whether your source was a 4000 pixel photo or a screenshot. That avoids the two usual failures — black bars from an off-ratio upload, and a blurry thumbnail from something too small being stretched.
three steps
PNG, JPG or WebP. It is decoded in the page — nothing is uploaded, so nothing waits on a connection.
The crop box is already locked to the 16:9 shape. Drag it over the part that matters and resize it from any corner; the pixel size is shown as you go.
The file comes out at exactly 1280 × 720. JPEG keeps it well under YouTube’s size ceiling; PNG is there when the artwork has flat colour and hard edges.
quick answers
1280 × 720 pixels, a 16:9 ratio, which is what this page exports. The minimum accepted width is 640, and uploading larger than 1280 gains nothing since YouTube resizes it back down anyway.
Almost always because the source was smaller than 1280 wide and got enlarged, either by you or by YouTube. Start from an image at least that wide — a frame grabbed from the video itself at full resolution is a safe source.
YouTube rejects thumbnails over roughly 2 MB. A 1280 × 720 JPEG at normal quality is a few hundred kilobytes, so you will not run into it unless you export PNG from a photograph.
No. The image is decoded, cropped and re-encoded in your browser. It never reaches a server, which also means there is no queue and no size limit beyond what your device can hold.