Signature image over 20 KB: shrink it

Signature image over 20 KB? Shrink it for the form

Application forms for exams, scholarships and government services often ask for a scanned signature of 20 KB or less. Each form sets its own number, so 20 KB is a typical figure, not an official limit.

Nothing is uploaded. Your browser does the compression, so the file stays on your device.

Lands under the real limit. We aim a little below it, so the upload goes through first time.

Fast. A 30 second 1080p clip fits into 10 MB in about two seconds on a desktop.

When you need 20 KB

A signature in dark ink on plain white paper is the easy case: it is mostly empty space. Crop close to the signature first, because the tool shrinks bytes but does not crop.

What to expect

A signature about 300 pixels wide stays crisp at 20 KB.

How big a picture fits in 20 KB

Rough pixel sizes at good quality. The tool checks the real result, so treat these as a guide.

What it is	About this many pixels
Detailed photo (landscape, crowd)	250 x 170
Typical photo or headshot	310 x 210
Scan, signature or screenshot of text	540 x 360

How we hit the number

We try the highest quality that fits. If the picture still will not fit even at a lower quality, we reduce the pixel size a step at a time until it does. Photos are saved as JPEG by default, which every form accepts. You can switch to WebP or PNG with the format menu.

The target we aim for is 19 KB, which is 600 B under 20 KB, so the file is not turned away over a few bytes.

Questions people ask

My form asks for 10 KB.

Use our 10 KB page or type 10 KB in the exact size box.

JPEG or PNG?

JPEG is the safe choice for almost every form.

Limits change. We link the official page wherever there is one, and the safety margin means a small change is unlikely to matter. Last updated 2026-11-09.