PNGGauntlet

PNGOUT works really hard to compress your images to the smallest possible size, which takes time. OptiPNG is also slow, but you can turn it off for faster compression if you don't need the absolute smallest files.

The progress bars reflect the progress of PNGOUT's multiple passes over the image, trying different compression techniques. The jumps represent the progress of each pass.

PNGGauntlet is developed in C# using the .NET Framework, so the framework must be installed for the software to run.

PNGOUT compresses 32-bit (RGB+Alpha) images to 8-bit with paletted alpha to minimize file size. While this works in most editors and web browsers, it doesn't work in Photoshop, GIMP, or Paint Shop Pro. To edit the compressed images in those programs, choose 'RGB+Alpha' color depth in the Options panel.

PNGGauntlet avoids converting files to PNG if it would make them larger. However, you can force conversion by checking 'Always convert files to PNG even if it would make them larger' in the Options dialog.

A red filename indicates that PNGGauntlet produced a larger file than the original. This only happens if you've checked 'Always convert files to PNG even if it would make them larger'.