Was improving site performance- stuck with comparing image size

To be honest not quite sure about the "beginners" tag, but I guess it will be the most interesting and useful for those who follow that tag.

I met a situation where converting format to "optimised" one made more harm, so I made a "quick" comparison of two "most optimised" formats.

Full article can be found here

But for those who dont want to check: use .webp and quality 70%