Resize an image to 20 KB — signatures, thumbnails and strict forms
Pick the limit a form or website gives you. The tool finds the largest, sharpest image that fits, on your device.
Processed in your browser — your image is never uploaded.
20 KB is the tightest limit you will meet in everyday forms. It is asked for signature images on exam and visa applications, thumbnails on older portals, and the small portrait that some government sites want next to a passport-size photo. At this size the goal is not beauty but legibility: a signature must still read as a signature, a face must still be recognisable.
What fits in 20 KB
A scanned signature on white paper fits easily, because most of the image is one colour. Save it as JPG at roughly 600 pixels wide and it will land around 10 to 15 KB. A colour portrait is harder: expect about 250 × 320 pixels at medium quality. That is enough for a form preview, but not for printing.
The tool starts from your full image and lowers compression first. Only when even the strongest compression is over 20 KB does it scale the picture down, in small steps, until it fits.
Tips for signatures
- Photograph or scan on plain white paper in good light. Shadows and paper texture cost bytes and look messy once compressed.
- Crop to the signature itself before you upload it here; empty margins add pixels without adding information.
- Choose JPG unless the form explicitly asks for PNG. A two-colour PNG can be tiny too, but a phone photo saved as PNG almost never is.
How to do it
- The 20 KB limit is preselected. Add the image: JPG, PNG, WebP or AVIF.
- Watch the size meter settle under the marker, then compare the result with the original using the slider.
- Download. If the form has a pixel-size rule as well, check the dimensions shown under the meter before you submit.
Questions about the 20 KB limit
The result is blurry. Can it be sharper?
Not at the same pixel size, and the tool already picks the highest quality that fits. Cropping tighter helps most: fewer pixels mean each one can keep more detail.
Does 20 KB mean 20,000 or 20,480 bytes?
The tool uses 20,000 bytes, which is what browsers and most upload checks count. A form that uses 20,480 will accept the file as well.
Is my signature uploaded anywhere?
No. The image is processed in your browser and never leaves your device.