What is Compress an image to 20KB?
TL;DR: Type 20 KB as your target and Shrink44 binary-searches the quality (and resolution if needed) to land at or just under 20KB — without uploading your image.
Reaching a 20KB ceiling is a common requirement for signature uploads and very small form fields. Most compressors only give you a quality slider; Shrink44 lets you set 20KB as an exact target and does the maths for you.
It works by iteratively binary-searching the encoding until the output lands at or below 20KB, all inside your browser — so even sensitive ID photos never touch a server.