Clean up and resize a signature to the exact pixels and KB range an online form asks for, with a white background and dark ink, in your browser. Everything runs locally in your browser - your files are never uploaded to a server, no registration is required, and the tool is completely free.
How to Signature Resizer
Take a photo or scan of your signature on white paper and drop it here.
Pick a preset or type your form's signature size in px (or cm plus DPI) and its minimum and maximum KB.
Adjust Clean background strength and Auto-trim so the paper is pure white and the ink is dark, then position the crop box.
Check the final pixel size and KB in the preview and download the JPEG.
Features
White paper, dark ink: Evens out shadows and grey paper from a phone photo, turns the background pure white and darkens the ink. Choose whether blue ink stays blue.
Auto-trim: Finds the signature and removes the empty paper around it, then fits it into the form's shape with a white margin instead of cutting off a flourish.
Exact size and KB window: Outputs the exact pixel size and searches JPEG quality to land between the form's minimum and maximum KB, without padding the file.
Private: Runs entirely in your browser. Your signature is never uploaded.
Frequently asked questions
Why is my signature file smaller than the form's minimum KB?
A clean signature on a white background compresses very well, so at small pixel sizes it can stay under the minimum even at maximum quality. The tool will not add filler data. Lower the clean strength, turn cleaning off, or check whether your form accepts a larger pixel size.
Can I keep blue ink?
Yes. Keep ink colour is on by default. Turn it off for a grey/black signature.
Are the presets official?
No. They are generic examples. Check your own form's instructions and edit the values to match.