Based on our record, PngOptimizer seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Personally, I like the psydk PNGOptimizer https://psydk.org/pngoptimizer for PNG files and FileOptimizer for JPEG files. The latter will work on all kinds of files but is exceptionally slow on PNG files. You can mess with the settings so it doesn't take so long but I don't bother. Source: almost 2 years ago
ImageOptim - Faster web pages and apps.
FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
pngquant - command-line utility and library for lossy compression of PNG images
Shrink O'Matic - Shrink O'Matic is an AIR application to easily (batch) resize (shrink) images.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.