pngquant — lossy PNG compressor

pngquant (Mac) Download: Open-source command-line utility and library for lossy PNG compression, allowing you to reduce the size of PNG files while maintaining transparency

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8 Free Bulk PNG Compressors - Optimize For Web And Performance

Free software PNGoo which can reduce the file size of images up to 70% and can also process multiple files at one time - GIGAZINE

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GitHub - kornelski/pngquant: Lossy PNG compressor — pngquant command based on libimagequant library

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GitHub - kornelski/pngquant: Lossy PNG compressor — pngquant command based on libimagequant library

8 Free Bulk PNG Compressors - Optimize For Web And Performance