What are some alternatives?
When comparing Ameto.de and TinyPNG, you can also consider the following products
Imagify.co - Resize, Crop and Manipulate your images on the fly!
ImageOptim - Faster web pages and apps.
Kraken - Kraken is a robust, ultra-fast image optimizer. Thanks to its vast array of optimization algorithms Kraken is a world ahead of other tools. Want to save bandwidth and improve your website's load times? Look no further and welcome to Kraken!
pngquant - command-line utility and library for lossy compression of PNG images
Cloudinary - Cloudinary is a cloud-based service for hosting videos and images designed specifically with the needs of web and mobile developers in mind.
PNGGauntlet - -Combines PNGOUT, OptiPNG, and DeflOpt to create the smallest PNGs