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Signature Cleaner & Resizer

Turn a photo of your signature into a clean, white-background image at the exact dimensions and file size an exam or bank form requires.

Private · on device. Runs in your browser: your file is not uploaded. No sign-up.

Sign in black ink on white paper, then photograph or scan it

Why signature uploads fail so often

A signature upload looks like the easiest part of an application form and turns out to be the fiddliest. The requirements are unusually tight, often a 140 × 60 pixel box and a 10–20 KB window, and a photograph of paper produces exactly the wrong kind of file for them.

There are three problems, and they compound:

  • The paper is not white. Indoor lighting tints it, and the portal sees a grey rectangle rather than a signature on white.
  • The signature is a small part of a big photo. Most of the frame is empty paper, so when the image is squeezed into a tiny box the strokes become a few illegible pixels.
  • The file ends up too small. Black lines on white compress remarkably well, so a correctly cropped signature can land at 4 KB and fail a 10 KB minimum.

The tool above deals with all three in one pass.

Getting a good source image

Everything downstream is easier if the input is decent. It takes thirty seconds:

  1. Use a black pen on plain white paper. Not blue, not a ballpoint that skips. Most forms require black ink explicitly.
  2. Sign larger than feels natural, around 6 cm wide. More ink means more detail surviving the downscale.
  3. Photograph it in daylight, phone held flat above the paper, with your own shadow out of the frame.
  4. Fill the frame with the paper. No desk, no hands, no background.

What each option does

Crop tightly to the signature

The tool scans for dark pixels and crops to the box containing them, plus a small margin. This is the single biggest improvement to legibility at small sizes, because every pixel then goes to the signature rather than to blank paper.

Clean the paper

Evens out uneven light and shadows, turns the paper pure white, and removes specks and the edge of the desk. It works on the lighting across the whole photo rather than a single brightness cut-off, so a shadow in one corner does not leave a grey patch.

Ink colour

Black redraws the strokes in a clean, even black, which is what most exam and bank forms ask for. Blue redraws them in a standard blue ink, for forms that ask for blue. As written keeps your pen's own colour, corrected for the lighting.

Clean-up strength

How hard the background is cleaned. Lower it if thin parts of your signature disappear; raise it if grey marks or paper texture remain.

Common exam requirements

ExamDimensionsFile size
SSC (CGL, CHSL, MTS, GD)6.0 × 2.0 cm (709 × 236 px)10–20 KB
IBPS / SBI140 × 60 px10–20 KB
Most other portalsRoughly 3:1Under 20 KB

Both of these enforce a floor as well as a ceiling, see the SSC signature requirement and IBPS signature requirement for the full rules and the official sources.

Before you upload

Open the downloaded file and look at it at full size. If you cannot read your own signature, neither can the person verifying your documents. If it is illegible, sign again larger and rerun rather than accepting it, a rejection at verification costs far more than another minute now.

Frequently asked questions

Why does my signature look grey instead of white?

Because white paper is not white under room lighting, it picks up a grey, yellow or blue cast depending on the bulbs. Your eyes correct for it automatically; the camera does not. Clean the paper (on by default) evens out the lighting and turns the paper pure white, shadows and tints included, which is what portals expect.

My signature file is only 4 KB but the form needs at least 10 KB.

This is normal, a clean black-on-white signature compresses extremely well. The tool closes the gap by adding a metadata comment block to the file. The image is byte-for-byte unchanged and the file stays completely valid; it is simply the size the portal expects.

Should I use a scanner or my phone?

A scanner gives a cleaner result, but a phone works if you photograph the paper flat in daylight with no shadow across it. Hold the phone directly above the paper rather than at an angle, or the signature will be skewed.

What does "crop tightly to the signature" do?

It finds the dark strokes and crops away the surrounding paper. This matters enormously at small sizes: squeezed into a 140 × 60 px box, a signature surrounded by empty paper becomes an unreadable squiggle, while a tightly cropped one stays legible.

Parts of my signature disappeared. How do I fix it?

The clean-up is treating faint strokes as background. Move the Clean-up strength slider towards gentle until they come back. If the pen was light grey or the ink very faint, sign again in black ink, which is what most forms require anyway.

Why must the signature not be in capital letters?

Indian recruitment boards including SSC and IBPS state this explicitly: a signature must be a signature, not a printed name. Applications have been rejected at the document verification stage for this alone.

Requirements this tool handles