Google has developed and launched a new encoder named Guetzli. It’s an open source algorithm that allows you to reduce the size of JPG files by up to 35% while keeping the quality unchanged. Additionally, you can increase the image quality while leaving the size unchanged.
Guetzli will allow you high compression density at a good quality of the image. It can be immensely helpful for saving images for the website. Using it will make the website use less data and thus be faster to load.