Resize your signature to size & KB

Resize your signature to the exact dimensions and KB limit your online form needs — free and entirely in your browser.

Files never uploadedNo sign-upWorks in your browserFree & unlimited
📁 Drop your signature image, or click to choose

Resize in 3 simple steps

1

Scan your signature

Sign on white paper with a dark pen and photograph or scan it.

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2

Set size & KB limit

Choose a preset or enter dimensions, and set the max KB (e.g. 20).

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3

Download

Save your signature, sized and within the limit, on a white background.

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Why use this signature resizer

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Exact dimensions

Resize to the precise width and height your application expects.

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KB ceiling

Automatically keeps the file under your form's size limit (often 10–20 KB).

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White background

Outputs a clean white-background JPG that online portals accept.

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Private

Processed in your browser — your signature is never uploaded.

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Free & unlimited

No sign-up, no watermark, no limits.

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Part of the kit

Use alongside the photo and PDF tools to finish your whole application.

Get your signature accepted on the first try

Online applications check your signature against strict rules: a small pixel size, a tight file-size range (often 10–20 KB), and a plain background. A photo of your signature is almost always too big and the wrong shape, so the upload fails. This tool fixes both at once — it scales your signature to the dimensions you choose and squeezes it under your KB limit, on a clean white background.

Like all ToolsKaro utilities, it works entirely inside your browser. Your signature is never sent to a server, so it stays completely private. Pair it with our Image Compressor and Passport Photo Maker to prepare every part of your application in minutes.

Typical signature size and KB limits

Signature boxes are smaller and stricter than photo boxes. A common requirement is a strip around 140×60 px kept inside 10–20 KB, but some recruiters allow a wider 300 px image. Check your notification and enter those exact numbers above. If you only need to hit a weight rather than a shape, the resize image in KB tool and presets like compress to 20 KB get you there in one tap.

Capturing a clean signature

The clearer your source, the cleaner the result. Sign with a dark pen on white paper, leave a margin, and either scan it or take a straight-on photo in bright, even light. Crop tightly around the strokes before uploading so the tool does not waste pixels on blank paper. If a scan comes out as a PNG, convert it with our PNG to JPG tool first, since most portals accept only JPG signatures.

Mistakes that get a signature rejected

Watch for a few common problems: a light pencil or thin gel pen that scans too faintly, a grey or yellow tint from poor lighting, a file that is the wrong shape or above the KB limit, and accidentally uploading the signature in the photo box. Fix the size and weight here, then prepare the matching photograph with the Passport Photo Maker so both files meet their own rules.

Related tools

Passport Photo MakerWhite-background passport / exam photo.Open tool Image CompressorCompress JPG/PNG to an exact KB size.Open tool Image ResizerResize photo by pixels or exam preset.Open tool Photo + SignatureCombine photo & signature in one image.Open tool

Frequently asked questions

What size should a signature be for online forms?
Most forms ask for a signature around 3×1 cm with a file size of 10–20 KB. Set the width, height and max KB to match your form's instructions, which are listed in the official guidelines.
How do I reduce my signature to 20 KB?
Upload a scan or photo of your signature, choose a size preset or enter custom dimensions, set the maximum KB (for example 20), and click Resize. The tool fits your signature within that size on a white background.
Will the white background be kept?
Yes — the signature is placed on a clean white background and saved as JPG, the format online portals accept. For best results, sign with a dark pen on white paper before scanning or photographing it.
My signature scan has a grey or yellow tint — can I fix it?
Use a well-lit photo or a proper scan on white paper. The tool keeps a white background, but a clean source image gives the clearest result.
Is it free and private?
Yes — free, no sign-up, no watermark, and your signature is processed entirely in your browser and never uploaded.
What pixel size should a signature be for online forms?
Many online portals expect a signature around 140×60 px, though some ask for up to about 300×80 px. The exact figure is in your official instructions — enter those numbers as the width and height, or start from a preset and adjust. Keeping the strip wide and short matches how a real signature looks.
How do I scan my signature for an online application?
Sign clearly with a dark blue or black pen on plain white paper, leaving a margin around the writing. Scan at around 200–300 DPI, or photograph it straight on in bright, even light with no shadows. Then upload the result here to set the exact size and KB limit your form needs.
Can I make the signature file smaller than 20 KB?
Yes. Set a lower maximum KB and the tool compresses the white-background JPG to fit. Signatures are mostly white space, so they shrink easily — if you need an even tighter target, reduce the pixel dimensions slightly first and the file size drops further.
Should the signature and photo be uploaded as separate files?
Almost always, yes. Portals have one upload box for the photograph and another for the signature, each with its own size and KB rules. Prepare the signature here, make the photo with the Passport Photo Maker, and keep them as two separate JPG files.

By Narender Chaudhary, Editorial & Product Lead · Updated June 2026