PngOptimizer makes smaller PNG than PngOut
Many designers/developers have discovered and used PNGOUT for awhile now to make smaller (sometimes significantly smaller) PNG files with better compression. I recently discovered another GPL program, PngOptimizer that makes even smaller files in many cases, especially for PNG8 files (256 colors with transparency, similar to GIF but better in some cases and IE supports it).
As a bonus it already has a drag-n-drop menu for multiple files where PNGOUT requires some extra 3rd party programs and the source is available. It’s perfectly safe to run files through PngOptimizer and then PNGOUT to find which one will make it the smallest as all the compression remains “loss-less” and PNGOUT won’t replace files that become larger, only smaller.
Comparison: FamFamFam.com v1.3 icon set
original: 662,196 bytes
pngout: 660,407 bytes (at “extreme” setting)
pngopt: 605,545 bytes
That’s over 50k better !