WebP is a modern image format that provides superior lossless and lossy compression for images on the web. Using WebP, webmasters and web developers can create smaller, richer images that make the web faster.
Lossless WebP supports transparency (also known as alpha channel) at a cost of just 22% additional bytes. For cases when lossy RGB compression is acceptable, lossy WebP also supports transparency, typically providing 3× smaller file sizes compared to PNG.
Lossy, lossless and transparency are all supported in animated WebP images, which can provide reduced sizes compared to GIF and APNG.
WebP is natively supported in Google Chrome, Safari, Firefox, Edge, the Opera browser, and by many other tools and software libraries. Developers have also added support to a variety of image editing tools.
WebP includes the lightweight encoding and decoding library
libwebp and the command line tools
dwebp for converting images to and from the WebP format, as well as tools for viewing, muxing and animating WebP images.
source page: https://developers.google.com/speed/webp