PNGSquash is the easiest, most effective way to reduce the size of your PNG images. Per the PNG format, all compressions are done losslessly (i.e., with no change in quality) so it is ideal for Web developers looking for essentially free bandwidth, app developers needing to save space, or anyone else looking to decrease the size of their images at no cost with a simple, one-time operation.
Instead of using just one single PNG compressor (like most other competing apps), PNGSquash combines ALL of the top PNG compressors together (PNGCrush, OptiPNG, AdvPNG, and PNGOut*, respectively) to allow for maximum possible compression.
Compresses images concurrently, taking advantage of every processor (or core) in your computer.
Provides configurations for you to choose from, edit, or add depending on your needs (the defaults are "Light", "Medium", and "Brutal") this means you have don't need to mess around with preferences every time you want to shrink the size of an image).
A simple, clean and straightforward UI.
*PNGOut cannot currently be bundled due to licensing restrictions, but there is a preference to enable it if you have it installed.
What's new in PNGSquash
Improved compatibility with OS X 10.7 Lion.
Significantly improved performance when dealing with large amounts of files.
Fixed race condition that would cause certain files to get "stuck" when many are being compressed at once.
No longer bails out after encountering an error on one image (useful for batch jobs).
Added setting to automatically time out on files that take too long (and hold up batch jobs).
Added button to clear finished results as they come.
Enumerating dragged directories can now be cancelled.
Sorting by name is now both alphanumeric as well as case-insensitive.
Now processes symlinks and aliases correctly.
Now correctly preserves permissions, Finder labels, Spotlight comments, and all other attributes of processed files.
Now correctly ignores hidden files and packages when enumerating directories.