WebP
A web-oriented format offering both lossy and lossless compression at smaller sizes than JPEG and PNG respectively.
Measured in
MB
In depth
WebP typically saves a quarter to a third over JPEG at equivalent visual quality, and it supports transparency and animation, which lets one format replace both JPEG and PNG on a website. It is limited to eight bits per channel and 4:2:0 chroma in its lossy mode, so it is a delivery format rather than a working one.
Examples in practice
Converting a portfolio site's images to WebP cuts page weight by about thirty per cent with no visible difference.