FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
ImageOptim - Faster web pages and apps.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
OptiPNG - OptiPNG is a command-line PNG optimizer that recompresses image files to a smaller size, without...
Compressor.io - Optimize and compress your images online. Compressor is a lossy and lossless photo compression tool.
TruePNG - Command-line PNG optimizer.