Will my ink colour change?

Not unless you ask. Ink keeps its own colour by default; "Normalise ink to black" paints every ink pixel black. The output is greyscale JPEG by default, which most signature fields expect, and that can be switched off in the tuner.

JPG unless the form says otherwise: almost every Indian portal lists JPG/JPEG for the signature. PNG can be chosen under Format, and a two-tone PNG of a clean signature is often very small.

Why does my signature look blurred at 10 KB?

Usually because the cleaned picture has more pixels than the field needs, so the bytes are spread thin. Pick the spec's pixels, or a smaller box, and the same bytes go further. Inspect the stroke edges at 400% before you download.

Can it make a signature from my typed name?

No, and it never will. This page only cleans the signature you photographed or scanned.

Resize Signature in KB — clean, cropped, 10–50 KB

Why signature files get rejected

A phone photograph of a signature is mostly paper: a grey-brown sheet with a shadow across it and a few strokes of ink. Squeezed to 20 KB as it is, the paper takes the bytes and the strokes go soft. Cleaned first — paper made white, ink kept, the rest cropped away — the same 20 KB is spent almost entirely on the strokes.

1The paper level is estimated across the sheet and divided out, which removes shadows and tint.
2Ink is found with an adaptive (Sauvola-class) threshold: each pixel is compared with its neighbourhood, not with one global level.
3The baseline is straightened by testing small rotations and keeping the one that lines the ink up best.
4The ink is cropped with padding, then handed to the tuner as a lossless picture made on this device.
5The tuner fits the spec's pixels — padding, never stretching — and searches the byte range.

Sign in dark ink — black or blue — on plain white paper, and photograph it flat in daylight.
Fill most of the frame with the signature; a small signature in a big photo leaves fewer ink pixels to work with.
Check the stroke edges at 400% in the tuner before you download.

Classical clean-up only.

The ink is found by an adaptive threshold, not by a model. Very faint pencil, ink the same tone as the paper, or a signature over printed lines can defeat it; raise or lower the threshold strength, or photograph it again on plain paper.

Questions people arrive with

Will my ink colour change?: Not unless you ask. Ink keeps its own colour by default; "Normalise ink to black" paints every ink pixel black. The output is greyscale JPEG by default, which most signature fields expect, and that can be switched off in the tuner.
JPG or PNG?: JPG unless the form says otherwise: almost every Indian portal lists JPG/JPEG for the signature. PNG can be chosen under Format, and a two-tone PNG of a clean signature is often very small.
Why does my signature look blurred at 10 KB?: Usually because the cleaned picture has more pixels than the field needs, so the bytes are spread thin. Pick the spec's pixels, or a smaller box, and the same bytes go further. Inspect the stroke edges at 400% before you download.
Can it make a signature from my typed name?: No, and it never will. This page only cleans the signature you photographed or scanned.

Elsewhere on this site

Photo size in KB for formsThe photograph for the same form, from the same sourced specs.
Photo and signature size for Indian formsEvery signature spec with its source and date.
Check image size in KBCheck a signature file you already have.