Why does my signature come out patchy or broken?

The ink is too light for where the threshold sits, usually a pencil or a fading pen photographed in poor light. Move the slider until the strokes are solid, or sign again with a darker pen.

Should the signature have a transparent background?

Not for a form. Forms expect a JPEG on white, and a transparent PNG is often rejected or shows up on a black background. Transparency is for placing a signature on a document you are signing yourself.

Resize a signature to 20 KB

Forms that ask for a photograph almost always ask for a signature too, and the signature limit is usually the smaller of the two: often somewhere between 10 and 20 KB. A signature is mostly empty paper, so that is plenty — provided the paper is actually white.

That is where phone photos fail. A signature photographed on a desk is grey, shadowed and surrounded by wood grain, and every one of those smudges costs bytes and makes the upload look careless. The tool below decides which pixels are ink, throws the rest away, and crops to the signature before it worries about file size. A clean signature at 300 pixels wide is usually a few kilobytes, well inside 20.

Sign in dark ink on plain white paper, photograph it straight on in daylight, and fill the frame. If the form gives exact pixel dimensions rather than a limit, clean the signature here first, then run the result through the photo resizer at those dimensions.

Set below already, and editable. The numbers on the form you are filling in are the ones that count — application rules change, and this page is not the authority.

1. Photo or scan of your signature

Drop a file here, paste it, or click to choose

Sign on plain white paper in good light, and photograph it straight on

Nothing is uploaded. The file stays on your device.

Open from Google Drive, Dropbox, OneDrive or a link

The link must be shared with “anyone with the link”. Your browser downloads the file straight from that service; it does not pass through this site.

2. Ink sensitivity: 140

Set from your photo automatically. Drag right if strokes are missing, left if the paper comes out grey or speckled.

Crop to the signatureTransparent background (PNG, for signing documents)Limit the longest sideKeep under (KB)

Result

Your cleaned signature will appear here.

Questions

Why does my signature come out patchy or broken?: The ink is too light for where the threshold sits, usually a pencil or a fading pen photographed in poor light. Move the slider until the strokes are solid, or sign again with a darker pen.
Should the signature have a transparent background?: Not for a form. Forms expect a JPEG on white, and a transparent PNG is often rejected or shows up on a black background. Transparency is for placing a signature on a document you are signing yourself.

Other sizes

Need a different number? The signature tool takes any size you type. Everything runs on your own device, and nothing is uploaded to this site or anywhere else.