How to Scan and Resize Your Signature for Online Forms
Get a clean, correctly sized signature image: how to capture it, remove the empty space and background, and meet pixel and KB limits.
Many applications ask for a scanned signature in addition to a photo, usually with strict limits such as "140 × 60 pixels, 10–20 KB". A signature photographed on a phone is typically a large, greyish image with lots of empty paper around it. This guide shows how to turn it into a crisp, compact image that meets the requirement.
Capturing a good signature
- Sign on clean white paper with a dark pen — black or dark blue gel or ink pens work best.
- Make the signature a comfortable size; very small signatures lose detail when enlarged.
- Photograph it in daylight or under even light, holding the phone parallel to the paper to avoid a slanted result.
- Avoid shadows from your hand or phone falling across the paper.
Cleaning it up
The Signature Resizer finds the ink automatically and trims away the empty paper around it (Auto Crop). It can also clean the background: "Clean white" turns grey paper pure white and makes the ink darker, which looks much sharper on forms. "Transparent" removes the paper entirely, which is useful when the signature will be placed on top of a document — this requires PNG or WebP, because JPG cannot store transparency.
Common signature sizes
| Size | Notes |
|---|---|
| 140 × 60 px | Very common on exam and recruitment portals, often with a 10–20 KB limit |
| 300 × 80 px | Wide format used by some online services |
| 350 × 150 px | Larger size where more detail is wanted |
Tip: These are common sizes, not official rules. Always follow the exact numbers printed in your form’s instructions.
Step by step
- Open the Signature Resizer and select the photo of your signature.
- Keep Auto Crop on. If something else is in the picture, use "Crop manually" first.
- Choose Clean white (recommended for most forms).
- Pick the required size, or enter a custom size. "Fit inside" keeps the signature’s shape and adds white margins instead of stretching it.
- Set the maximum file size, then press Process Signature and save the result.