(Some) files are compressed by 0%, why is that?
If a PNG file is already optimised, for example by another application or because its contents can be optimised no further, no more gains can be made. PNGShrink will then show a compression of 0%.
Support for PNGShrink
If a PNG file is already optimised, for example by another application or because its contents can be optimised no further, no more gains can be made. PNGShrink will then show a compression of 0%.
Pngquant is a library for compressing PNG images. It is used by many tools and websites to compress and optimize PNG files. PNGShrink for OS X uses this same library so you can optimize batches of PNG files in an easy and fast way without having to upload them to somewhere.
No. The optimization is done on your own Mac. This means optimization is not only much faster, it also guarantees privacy, security and non-disclosure of your (or your customers) content.
No. You select a target folder and the optimized files will be stored there. Your original images will remain the same.
PNGShrink for macOS can batch process PNG images, decreasing their file sizes, keeping transparency and quality. More information.