Thanks! I've been looking into mozjpeg for a project, and this is very useful for me to quickly test out options.

On a design note, the background color of the quality slider is very difficult to see on crappy displays. Took a while to understand what that "radio button" did. I moved the window to my MacBook display and it looked fine, but on my crappy external monitor it's near impossible to see.

Awesome, thanks :)