Exam photo and signature resizer

Setting the pixel size is easy. Landing inside a KB range is not, because the JPEG quality setting is not a file size dial. The same quality of 0.7 gives a 12 KB file for a plain background and a 60 KB file for a busy one, and no formula can tell you which in advance. The only way to know is to encode and measure.

So this tool measures. It encodes at full quality first, and if that already fits under your maximum it stops. Otherwise it bisects: it encodes at the lowest quality to prove the target is reachable at all, then repeatedly halves the interval, keeping the best quality whose real encoded size still fits.

Twelve steps narrow the quality argument to better than 0.001, which is finer than the encoder itself reacts to, and the whole search takes a fraction of a second because it runs on a picture that is only a couple of hundred pixels wide.

A 200 x 230 headshot on a plain background can encode to 12 KB at full quality. If the form demands at least 20 KB, there is no honest way to add 8 KB of detail that was never in the picture, and raising the quality further is not possible once it is already at the maximum.

The tool pads the file instead. A JPEG comment segment, marker FF FE, is part of the JPEG standard: it carries a length and then bytes that every decoder skips on its way to the image data. Adding enough of them lifts the byte count over the minimum without touching a single pixel, the dimensions, or the visible quality. The page tells you exactly how many bytes of padding went in, and you can switch it off.

The alternative approaches used elsewhere are worse. Adding visible noise degrades the photo to game a byte count. Silently uploading a file that is under the minimum just gets you rejected at submission.

The presets are labelled as common requirements, not as any board's official specification. 200 x 230 px at 20 to 50 KB for a photo, and 140 x 60 px at 10 to 20 KB for a signature, are the combinations that turn up on most Indian application forms, which is why they are here.

Specifications change between sessions and between boards, and putting an exam name next to a number we have not verified would be worse than useless to somebody with one shot at a form. Read the instructions on your own form, type those four numbers into the boxes, and the tool will hit them.

Match the aspect ratio before you shoot. 200 x 230 is slightly taller than it is wide. A wide landscape photo has to lose most of its sides to fit, so a head and shoulders portrait crops far better.

Sign on white paper with a dark pen. A scanned or photographed signature on grey paper carries a lot of texture, and texture is what makes JPEG files big. Whitening the background removes it, which matters when the limit is 20 KB.

Check the extension the form wants. This tool outputs JPEG with a .jpg extension, which is what nearly every form asks for. If yours insists on .jpeg, renaming the file is enough, since the contents are identical.

Keep the original. Portals often ask for a different size at a later stage. Re-crop from your original photo rather than from an already compressed 20 KB copy, because compression damage accumulates.

How do I make a photo exactly 200 x 230 pixels and between 20 and 50 KB?

Upload the photo, pick the 200 x 230 px preset or type your own numbers, position the frame over your face, and the tool encodes it for you. It sets the pixel size exactly, then searches for the JPEG quality that puts the finished file inside the KB range you asked for. The exact byte count is shown before you download, so you can check it against the form.

What happens when my photo compresses to less than the minimum size?

A small picture with a plain background can land under 20 KB even at full quality, and there is no honest way to add detail that is not there. The tool instead pads the file with JPEG comment segments, which are part of the JPEG standard and are skipped by every decoder. The pixels, the dimensions and the visible quality do not change, only the byte count. You can switch the padding off if you would rather submit the smaller file.

Does KB mean 1000 bytes or 1024 bytes here?

1024 bytes. Application forms and the file managers students check their sizes in almost always mean 1024, so a 50 KB limit is treated as 51,200 bytes. The tool also prints the raw byte count next to the KB figure, so if your form means 1000 you can still see exactly where you stand.

Are these presets the official specification for a particular exam?

No, and the tool deliberately does not put an exam name next to a number. 200 x 230 px at 20 to 50 KB for a photo and 140 x 60 px at 10 to 20 KB for a signature are the combinations that turn up on most Indian application forms, so they ship as common requirements. Read your own form and type its numbers into the custom fields if they differ. Every value here is editable.

Is my photo uploaded to a server?

No. The file is read, cropped and encoded entirely inside your browser using the Canvas API. Nothing is sent anywhere, nothing is saved, and there is no account. You can turn off your connection after the page loads and the tool still works.

My signature photo has grey paper behind it. Can this fix that?

In signature mode there is an option to whiten the paper. Any pixel brighter than the threshold is set to pure white, which lifts a grey photographed page to a clean background and leaves the ink alone. It also compresses far smaller, which is usually helpful because signature limits are the tightest.