Signature Resizer & Extractor

A signature upload looks like the easiest part of an application form, and it is the part that trips people up most. The portal wants a tiny file — often between 10 and 20 KB — at an odd pixel size like 140 × 60, and your phone produced a 3 MB photo with a grey table, a shadow of your hand and a lot of empty paper around the signature. Shrinking it naively gives you a smudge. Compressing it hard gives you blocky JPEG noise around the letters.

The signature resizer on this page solves that in one pass: it separates the ink from the paper, crops to the signature, darkens it, and then fits the result to the exact pixels and kilobytes the form asks for. It is the same engine as our main photo editor, started in signature mode, and it runs entirely in your browser.

What signature size do exam and ID forms ask for?

Every recruitment body writes its own rule. The table below lists the signature specifications in our data set, with their source confidence. It is generated from the same file that powers the editor's presets, so picking a preset gives you exactly what is listed here:

From data/presets.json (last checked 2026-09-26). Verify with the official notification.

A few patterns stand out. Banking recruiters (IBPS, RBI, LIC) use 140 × 60 px and 10–20 KB. NTA exams (JEE Main, NEET UG, CUET) use 350 × 150 px with a wider KB range. The new SSC module asks for a signature of about 6.0 × 2.0 cm, which is 472 × 157 px at 200 DPI. UPSC is the outlier: it asks for a triple signature — the same signature three times on one page — at 400 × 500 px. Rows marked "secondary" were taken from a reliable summary because the official file could not be read; verify those with the notification before relying on them.

How do I scan or photograph my signature on a phone?

You do not need a scanner. A phone photo taken carefully is usually better than a low-quality office scan. What matters:

• Light: daylight from a window, not a yellow bulb overhead. Even light means the paper comes out an even grey that the cleanup can turn into pure white.
• Angle: camera parallel to the paper. Tilting makes the signature trapezoid-shaped.
• Distance: close enough that the signature is large in the frame, far enough that the phone's shadow isn't on the paper.
• Focus: tap on the signature so the edges of the ink are sharp.
• No flash: flash creates a bright spot in the middle and dark corners.

Phone "document scanner" modes also work; just avoid ones that add a coloured filter.

How do I remove the background from a signature image?

"Signature background remover" and "signature extractor" usually mean the same thing: keep the ink, throw away the paper. For a signature you do not need an AI model — the ink is simply darker than the paper. The resizer measures how bright the paper is in your photo and treats everything clearly darker than that as ink. Everything lighter becomes pure white, which removes the grey cast, the shadows and faint lines from the page. Then it crops to the ink with a small margin and centres it.

If your paper has ruled lines, raise the cleanup strength until the lines disappear, or crop them out. If the ink gets thin or broken, lower the strength and enable "Blacken / darken ink".

How do I reduce signature size to 20 KB (or increase it to 10 KB)?

File size in KB depends on the pixel dimensions, the format and the JPEG quality. A 140 × 60 px signature on white is naturally tiny — often only a few KB — so the common problem with bank forms is actually the minimum: "10 KB to 20 KB" rejects a 4 KB file. The editor handles both ends:

• Too big: it lowers the JPEG quality step by step until the file is under the maximum (it treats "20 KB" as 20,000 bytes, so it also passes portals that count 1 KB as 1,000 bytes).
• Too small: it pads the JPEG with harmless metadata so the file reaches the minimum (counted as 1,024 bytes per KB, the stricter reading) without changing a single pixel.

Our automated test on the IBPS signature preset produced 10,343 bytes against a 10–20 KB range. If you need an exact size, type it in "Make it exactly N KB".

How do I resize a signature in cm, like 3.5 × 1.5 cm or 6 × 2 cm?

Centimetres only make sense together with a DPI value, because a screen image has pixels, not physical size. The conversion is pixels = cm ÷ 2.54 × DPI. So 3.5 × 1.5 cm at 200 DPI is 276 × 118 px, and 6 × 2 cm at 200 DPI is 472 × 157 px. In the editor's dimensions section you can switch the unit to cm, mm or inches and set the DPI; the pixel size follows, and the DPI is written into the file's metadata. You can also paste "3.5 cm × 1.5 cm at 200 DPI" into the requirement box and the parser converts it for you.

Can I make a signature transparent?

Yes — choose PNG as the format and the transparent swatch as the background. That is useful for placing a signature on a document or a PDF. Exam portals, however, almost always ask for JPEG, and JPEG has no transparency, so for form uploads keep the white background.

Why does the portal reject my signature?

• File too small. Under the minimum KB. The editor pads to the minimum automatically when a range is set.
• Wrong dimensions. Some portals check exact pixels. Use the preset or type them.
• Wrong format. A PNG renamed to .jpg is still a PNG inside. Download a real JPEG.
• Signature in capital letters. Many notifications say a signature in block capitals is not accepted. Sign the way you normally do.
• Signed by someone else or unclear. Blurry or faint signatures can be rejected at document verification later. Use a darker pen and good light.
• Different from the exam-day signature. You will sign again at the centre; keep it consistent.

Rules differ between bodies and change between cycles. The specs above come with their source and last-checked date on each exam page — verify with the official notification before you submit.

Need your photo too? Use the photo & signature resizer for the photo, or join photo and signature when the form wants both in one image. For printed passport photos, see the passport size photo maker.