pngquant is a convenient command-line utility for lossily reducing the data size of PNG images by selectively removing colors. Finding the optimal level of color reduction is subjective and requires human interpretation, so I often find myself running the utility a few times with varying parameters in search of the smallest acceptable output.

To aid in this process Iโ€™ve drafted a simple graphical interface that allows adjusting parameters with a live preview.

screenshot of pngquant-interactive

It pairs particularly well with a Nautilus script:

screenshot of Nautilus script menu containing โ€œPNG: Quantizeโ€