Caesium Image Compressor is described as 'Lets you compress your pictures up to 90% without visible quality loss. Providing a simple yet effective interface with a real-time preview and multiple image processing at the same time, everyone will be able to reach the best result' and is a popular Image Optimizer in the photos & graphics category. There are more than 100 alternatives to Caesium Image Compressor for a variety of platforms, including Windows, Web-based, Mac, Linux and Android apps. The best Caesium Image Compressor alternative is Image Toolbox, which is both free and Open Source. Other great apps like Caesium Image Compressor are ImageOptim, Dinky, FileOptimizer and OptiImage.
Not working properly( I tried to optimize 270 jpg images, it optimized first 30 and after program gave failure statuses. Just like Otimage. Not good. And again I recommend Imagine(from github) worked well, free. And Pichi, 7 days free, after 25 dollars as of now. both better