Signature Resize
Turn a photo of your signature into a clean, small file for an online form: white background, no wasted margins, under your KB limit.
More options: pixel size, DPI, how KB is counted
Leave width and height empty to let the tool choose. Fill in one of them to keep the proportions; fill in both for an exact size.
From phone photo to form-ready signature
- Sign on plain white paper with a dark pen, a little larger than usual.
- Photograph it from directly above in daylight, without flash (which causes a glare spot), filling most of the frame.
- Add the photo above. The tool turns the grey paper white, trims the empty space around your signature and saves it within the size range.
- Check the preview and download. If strokes look broken, turn off whitening and run it again.
What the clean-up options do
| Option | Effect |
|---|---|
| Make the paper pure white | The tool measures your photo to find the level that separates ink from paper; everything lighter than that becomes white, and the ink stays as it is. Removes grey paper tone and soft shadows. |
| Trim empty margins | Crops to the signature itself plus a small border, so the pixels you keep are the ones that matter. |
| Black & white | Removes colour, for forms that ask for a black signature on white. |
Plain white areas cost almost nothing to store, so a cleaned-up signature fits in a small file at a large, sharp size, while a grey, noisy photo would need to shrink much more to fit the same limit.
Photo and signature together
If your form asks for both a photo and a signature, resize the photo with the KB resizer or at an exact size in centimetres with resize image in cm, then come back here for the signature. For a signature file that must be larger than it naturally comes out, see increase image size in KB.
Frequently asked questions
How do I resize my signature to 10–20 KB?
Photograph or scan your signature on plain white paper, then add the image above with the 10–20 KB preset selected. The tool whitens the paper, trims the empty space around the signature and saves a JPG between 10 and 20 KB.
Why does my signature photo look grey?
A phone camera records white paper as light grey, often with a shadow. The 'make the paper pure white' option turns everything lighter than the ink into white, which looks cleaner and also makes the file compress better.
My form asks for a signature in exact pixels, such as 140 × 60. Can I do that?
Yes. Open More options and type the width and height. With trimming on, the signature is first cut to its own outline, then fitted into your box. Choose 'Fit with white borders' so no part of the signature is cropped off.
What pen should I use?
A black or dark blue pen with a bold line, on plain white paper. Thin, light strokes can partly disappear when the paper is whitened; if that happens, turn the whitening off or sign again with a darker pen.
Is my signature uploaded anywhere?
No. The image is processed by your own browser and never leaves your device. That matters for a signature, so we built it that way deliberately.