Why forms ask for a size in kilobytes
Exam boards, banks and government portals cap upload sizes to keep storage and bandwidth predictable across millions of applicants. The limits are usually strict and unhelpfully specific — 20 KB for a signature, 50 KB for a photograph — and the upload simply fails without telling you how far over you are.
Quality first, dimensions second
There are two ways to make an image file smaller: encode it more coarsely, or make it smaller in pixels. This tool tries the first exhaustively before touching the second, because reducing quality keeps every pixel of the original composition. It binary-searches the JPEG quality setting to find the highest value that still lands under your limit.
Only when that fails does it start scaling. That happens with modern phone photos and very tight limits — twelve million pixels cannot be described in twenty thousand bytes at any quality. When it does scale, it says so and reports the new dimensions, rather than quietly handing back a thumbnail.
Getting a signature under 20 KB
Signatures are the tightest limit and the easiest to satisfy, because a signature is mostly white. Photograph or scan it against plain paper, crop away everything that is not the signature before uploading here, and the result will usually come in well under the limit with room to spare. Cropping first matters more than any setting — the tool cannot know that half the image is desk.
The photo never leaves your device
These uploads are attached to identity documents, which makes them exactly the wrong thing to hand to an anonymous website. Every step here happens inside your browser tab through the canvas API. There is no server to receive the image, so there is nothing to leak, log or forget to delete.