Signature uploads usually need a small JPG, often between 10 and 20 KB. Sign in black or dark-blue ink on plain white paper, photograph or scan it, crop tightly around the signature, then compress it here. The target is set to 20 KB; type 10 if your form asks for less.
How to do it
Crop the photo so only the signature is left (use the Crop Image tool if needed).
Add the cropped image here — the target is 20 KB.
Press “Process” and download the JPG.
Frequently asked questions
Why is my signature rejected even under 20 KB?
Forms often also check pixel dimensions (for example 140 × 60) or a minimum size such as 10 KB. Use Resize Image for exact dimensions, and do not compress far below the minimum.
How do I make the background white?
Use plain white paper and good light. Cropping close to the ink also removes shadows.