Signature uploads made easy
Exam boards, public service commissions, banks and recruitment portals in India, Pakistan, Bangladesh and elsewhere ask for a scanned signature, usually as a JPG within a small size range such as 10–20 KB, and sometimes with fixed pixel dimensions. A phone photo of a signature is too big, has grey or yellowish paper, and includes the table around it. This page opens our crop tool in signature mode: you drag a box around the signature, it turns the paper pure white and darkens the ink slightly, and saves a JPG under 20 KB at the best quality that fits. Optionally you can set an exact width and height in pixels.
Updated September 2026
How to resize a signature to 20KB
- 1Sign in black or dark blue ink on plain white paper and take a clear, straight photo.
- 2Select the photo, then drag the box tightly around your signature.
- 3Check that “Clean white background” is ticked and the maximum size is 20 KB; add exact pixels if your form asks for them.
- 4Press Make signature, check the preview, then download the JPG.
Taking a good signature photo
- Use a black gel or ballpoint pen and sign a little larger than usual on plain white paper.
- Put the paper on a flat surface in good daylight, with no shadow of your phone on it.
- Hold the phone straight above the signature, parallel to the paper.
- Don't use flash; it causes a bright spot in the middle.
What the cleaning step does
The tool looks at how light or dark every pixel is and automatically finds the level that separates ink from paper. Everything lighter than that becomes pure white, which removes grey paper, uneven light and faint shadows. Darker pixels are kept and made a little darker, so thin pen strokes survive compression. The result is saved as a JPG under your size limit.
Exact pixel sizes
When a form gives a width and height in pixels, tick Exact size in pixels and enter both. The crop box then keeps that exact shape, so your signature isn't stretched, and the saved image has exactly those dimensions. With a fixed size the tool lowers only the quality, never the pixels, to meet the file size limit; if it still can't, it says so.
Also need a photo?
Most application forms want a passport-style photo too. Use Compress Image to 20KB for the file size, or the Passport Size Photo Maker when you also need an official printed size.
Features
- Crop to just the signature, with touch support
- Clean white background: grey paper and shadows removed
- Ink darkened slightly so it stays crisp
- Maximum file size preset to 20 KB
- Optional exact width and height in pixels
- JPG output, made entirely on your device
Frequently asked questions
What is the usual signature size for online forms?
It varies by form. Common rules are a JPG between 10 and 20 KB, and some forms also give pixel dimensions such as a width around 140 pixels and a height around 60 pixels. Always follow the numbers in your form's notification and type them into the size and pixel boxes here.
How do I make my signature 10 KB instead of 20 KB?
Change the Maximum size box from 20 to 10 before pressing Make signature. On clean white paper a signature compresses very well, so 10 KB still looks sharp.
My form says the signature must be between 10 and 20 KB. Is a 6 KB file OK?
No. Some forms reject files below the minimum. If your result is too small, tick Exact size in pixels and enter a larger width and height, or set the maximum a little higher; bigger pictures take more kilobytes.
Why does the background need to be white?
Forms print or display signatures on a white page, and a grey or shadowed background looks messy and wastes file size. The cleaning step finds the ink and makes everything lighter than it pure white.
Can I use blue ink?
Yes, but the cleaned signature is saved in black and white tones, because that gives the crispest, smallest file. If your form insists on showing the ink colour, untick Clean white background and just crop and resize.
Is it safe to upload my signature here?
You don't upload it anywhere. The photo is cropped, cleaned and compressed inside your browser, and the result is saved straight to your device. Nobody else sees your signature.