Compress Image to 500 KB

A 12-megapixel phone photo is 4032 × 3024 px and, as a high-quality JPEG, typically weighs 2–5 MB depending on how busy the scene is. To hit 500 KB the encoder rounds away texture the eye is least sensitive to: grain in shadows, tiny variations in a blue sky, the weave of a fabric.

At 500 KB that rounding is usually invisible at screen size. The tool tries quality first, from high to low, and keeps the full width whenever a quality above Lowest quality allowed gets there. Only very detailed images, such as a forest, a crowd or a high-ISO night shot, need Allow downscaling to step the width down, often to around 3000 px, which is still more than any laptop screen shows.

Metadata goes too: Strip metadata removes the camera model, GPS location and embedded thumbnail, which can take tens of KB on a phone photo. Turn it off only if you need the capture date to travel with the file.

If the form also states pixel dimensions, set them first with Resize first under Advanced settings. A 1920 px wide photo almost always fits in 500 KB at high quality, so you get both rules at once without the encoder having to work hard.

Scans behave differently from photos. A color A4 scan at 300 DPI is 2480 × 3508 px, larger than a phone photo, and paper texture costs bytes. Scanning at 200 DPI, or in grayscale for a text-only page, keeps the result readable at 500 KB. If the form wants several pages in one file, compress a PDF instead with compress PDF to 500 KB.

Finally, compress from the original. Re-compressing a file that was already squeezed by a messaging app stacks two rounds of loss. The guide to reducing image size in KB covers where to find the original on iPhone and Android.