Google reduces JPEG file size by 35%

Google has developed and open-sourced a new JPEG algorithm that reduces file size by about 35 percent--or alternatively, image quality can be significantly improved while keeping file size constant. Importantly, and unlike some of its other efforts in image compression (WebP, WebM), Google's new JPEGs are completely compatible with existing browsers, devices, photo editing apps, and the JPEG standard. The new JPEG encoder is called Guetzli, which is Swiss German for cookie (the project was led by Google Research's Zurich office). Don't pay too much attention to the name: after extensive analysis, I can't find anything in the Github repository related to cookies or indeed any other baked good. There are numerous ways of tweaking JPEG image quality and file size, but Guetzli focuses on the quantization stage of compression.