imageoptim.com
ImageOptim is a free, open-source Mac app that compresses images without losing quality, reducing file sizes for faster loading and less disk space use. It removes private EXIF metadata, comments, thumbnails and unnecessary color profiles. It combines tools including MozJPEG, pngquant, Pngcrush, 7zip, SVGO and Google Zopfli, and accepts drag-and-drop input. Lossy minification is an optional setting.