Online job and government portals ask for a scanned signature because they need to verify your identity against paper documents. Most of them enforce strict limits — typically 3.5×1.5cm in size and under 20–30KB — and will reject uploads that do not match exactly. Getting this right is straightforward once you know what to look out for.

Why Portals Reject Signature Images

The three most common rejection reasons are:

• Wrong dimensions. The portal checks pixel dimensions or physical size at a given DPI. A phone photo is usually several MB and thousands of pixels wide — far too large.
• File too large. SSC and Indian Railways portals cap the signature at 20KB. A standard JPEG from a phone is 1–5MB, which is 50–250× over the limit.
• Background colour. Some portals run automated checks and expect a white background. A cream, grey, or shadowed background from a phone photo can trigger a rejection.

Step 1 — Sign on the Right Paper

Use a fresh sheet of plain white A4 or letter paper. Avoid lined, ruled, or coloured paper — the lines or tint make background removal harder. Sign with a black or dark blue ballpoint or gel pen. Black gives the highest contrast against white paper and produces the cleanest result. Light ink colours (red, orange, pencil) can blend into the paper background and should be avoided.

Sign at roughly the size you normally would on a form — about 6–10cm wide. Do not sign in a tiny area; more detail survives the downscaling to 3.5cm.

Step 2 — Photograph or Scan It

You have two options:

• Phone camera (quickest). Place the paper flat on a desk. Hold the phone directly above — not at an angle — so the paper fills most of the frame. Use a well-lit room with even light from both sides. Avoid casting your own shadow onto the paper and avoid strong side-lighting, which creates shadows across the ink. Tap to focus on the signature before shooting.
• Flatbed scanner (cleanest). Scan at 200–300 DPI in colour or greyscale. A scanner eliminates perspective distortion and lighting variation entirely and produces the best result for background removal.

Step 3 — Remove the Background

Even a careful phone photo will have some background variation — slight yellowing of the paper, a faint shadow near one edge, or an off-white tone from artificial light. Portal checkers may flag these as a non-white background.

The signature tools on this site include a one-click background removal that is specifically designed for ink on paper. It uses an adaptive contrast algorithm: for each pixel, it compares the brightness to the surrounding area rather than using a fixed "white" threshold. This means:

• Cream or off-white paper is cleaned to pure white.
• A gradual shadow across one side of the image is corrected.
• Thin, light ink strokes are preserved (the algorithm detects them as locally darker than their surroundings).

It runs entirely on your device — no image is ever sent to a server.

Step 4 — Crop to the Signature

Drag the crop handles in the tool so the signature fills most of the frame, with a small equal margin on all four sides. Do not clip any part of the signature — make sure ascenders (letters like l, h, k) and descenders (letters like g, y, p) are fully inside the crop. A small amount of white space around the signature is fine and expected by portals.

Step 5 — Resize and Compress

After removing the background, click Apply. The tool resizes the image to the selected preset dimensions and compresses it to meet the file size target. For SSC, UPSC, IBPS, SBI, and Railway portals the required size is 3.5×1.5cm (35×15mm) — 276×118 pixels at 200 DPI. Check your portal's instructions for the exact limit:

• SSC, Indian Railways (RRB/RRC): under 20KB
• UPSC, IBPS, SBI: under 30KB
• State PSCs and private portals: often 50KB or 100KB — check the notification

If the compressed output looks blurry, crop tighter around the signature before applying so fewer background pixels are included in the JPEG.

Common Questions

Can I use a digital (e-signature) image?

Most government portals explicitly require a wet ink signature — meaning a physical signature scanned or photographed from paper. A typed or software-generated signature is usually rejected. Check your portal's FAQ to confirm.

My signature file passes the size check but the portal says "invalid image"

Most portals require JPEG format specifically, not PNG or WebP. The tool outputs JPEG by default — make sure you are downloading the JPEG file, not a PNG that was saved by a screenshot tool.

The background removal left some grey patches in the image

This can happen if the original photo had very low contrast — for example, light ink on off-white paper photographed in dim light. Retake the photo in brighter, more even light and try again. Dark ink in good light produces a clean result in one click.