Compress an image to 10 KB

At about one bit per pixel, 10 KB is 80,000 bits. That fits a picture of 280 by 280 pixels, or a portrait of 250 by 320. Calm backgrounds let you go a little higher and cluttered ones pull you lower.

Many portals set a photo at 10 to 50 KB and a signature at 10 KB or less. Photograph the signature on white paper, crop tightly, and run it through at this target. Colour is wasted on a pen stroke, so switch the picture to black and white first and the same 10 KB buys a smoother line.

Keep a copy of the original. Forms sometimes reject a file for its dimensions after accepting its weight, and you will want the sharp version to try again.

The row shows the size reached and the final width and height. If the size is far below 10 KB, there is room to raise quality or dimensions. Pick Custom in the Target size menu and type 9 or 9.5 to use more of the allowance.

Besides forms, a 10 KB limit shows up in staff badges, club membership systems and old intranet tools. Those pages show the photo at thumbnail size, so there is no point uploading more pixels than they display. Crop to the face, set the width to 250 or 300 pixels, and let the compressor fill the rest of the budget with quality.

A square crop usually survives better than a tall one at this size, because the encoder works in small square blocks and a square frame wastes fewer of them on the edges.

A system that counts in kibibytes treats 10 KB as 10,240 bytes, and you are fine. One that counts strictly in thousands and adds its own header can still trip you by a few bytes. This page aims below 10,000 bytes, so it holds up under both rules.