Exact dimensions, not approximate ones
When a portal specifies a width and a height in pixels, it means those numbers. A file that is a few pixels out in either direction is commonly refused by the validation script before a human ever sees it, and the error message rarely explains which condition failed.
This page opens the tool with an exact output size already set, so the result comes out at those dimensions rather than near them. Confirm the figures against the notification you are applying under before you upload, because they are revised between cycles.
Aspect ratio is the part that catches people
A signature box is wide and short, roughly three times as wide as it is tall. A photograph of a signature on a page is usually nothing like that shape, so something has to give when it is forced into the box.
Stretching it would distort the handwriting, which is unacceptable when the whole point is that it matches a physical specimen. Instead the image is scaled until it covers the box and the middle is kept. That means you should crop close to the signature yourself first, otherwise the part that gets kept may not be the part with your name in it.
Sign wide, not tall
Because the target is a wide shallow rectangle, a signature written compactly across the page fits it far better than one with large loops above and below the line. If you are signing specifically for this, keep the ascenders and descenders modest and let the signature run horizontally.
Questions
- Why does the form reject my signature when the file size is fine?
- Because file size is one condition among several. Pixel width and height, aspect ratio, format and sometimes a minimum as well as a maximum file size are all checked. A signature at the right kilobytes but the wrong dimensions fails, and portals frequently return a generic error rather than naming the condition that was not met.
- Will cropping to an exact size cut off part of my signature?
- It can, if the source is a very different shape from the target. The image is scaled to cover the required box and the centre is kept, so a tall photograph with a lot of paper above and below will lose that paper first. Crop tightly around the signature before you start and the result will contain what you expect.
- Are the dimensions the same for every SSC recruitment?
- Not reliably. Different examinations and different cycles have carried different requirements, and the commission republishes the specification with each notification. Read the upload instructions attached to the advertisement you are applying under and treat any figure quoted elsewhere, including on this page, as a starting point to verify rather than an answer.