Compress JPG to 100KB Online

There is no box to type a target size into, which is worth knowing before you start. You lower the quality, watch the output size, and stop when the number is where you need it. In practice that is two or three passes and about ten seconds.

Two levers move the size. Quality is the obvious one, on a slider from 1 to 100, and for a photograph the drop from 90 to 70 is usually invisible and often halves the file. Dimensions are the underrated one: an image displayed at 800 pixels wide does not need to be 4000 pixels wide, and resizing does more than any quality setting.

Presets give you a starting point rather than a target: web optimized at 80 percent quality and a maximum of 1920 pixels wide, email at 60 percent and 800 pixels, thumbnail at 70 percent and 300 pixels square. Moving the slider from a preset switches you to custom.