I know this is a new format for images, but I don't know how to show it in HTML.
Does anyone know how I can do that? Which browsers can show this image format besides chrome?
You use webp like any image:
<img src="img.webp" />
However since it's not always supported (see http://caniuse.com/#feat=webp), you can use this to set a fallback:
<picture>
<source srcset="img.webp" type="image/webp">
<source srcset="img.jpg" type="image/jpeg">
<img src="img.jpg">
</picture>