PngOptimizer is an easy-to-use program to compress common graphics formats to PNG format with no quality difference. Files can be added one at a time or in batch to the program icon or window. Images can also come from the clipboard by pressing CTRL+V while the application is in focus.

Cross-platform with clients available for Linux. A CLI version is available.

Graphics formats supported include BMP, GIF, TGA, as well as further compressesing PNG files. Animated GIF and PNG files (APNG) are also supported. Size decrease for PNG files varies widely on the original editor, but GIF and BMP conversions can be as much as 40% and 95% respectively.

Alternatively, PngOptimizer Portable automatically switches between 32-bit and 64-bit and adjusts the screenshots path.