ImageOptim A free app that makes images load faster and take less disk space, without sacrificing quality
TinyPNG Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency.
JPEGmini JPEGmini reduces the file size of your photos by up to 80%, while keeping their original quality and JPEG form
TinyJPG Reduces the file size of your JPEG images. Every uploaded image is analyzed to apply the best possible JPEG encoding