As most web developers will know there are three main image formats used on the web – the Graphics Interchange Format (GIF), Joint Pictures Expert Group (JPEG) and Portable Network Graphics (PNG). Most will also know about their various advantages and disadvantages. Google are hoping to unify these formats in their new WebP image format and a recent announcement shows that they are getting closer to this goal.
Technically any image format can be used on the web, but support from browsers dictates how popular a format will be. All of the major browsers support the above three and Google will need to make sure that they can support WebP in order for it to become viable.
So why do we need another web image format? As mentioned above, each of the current major formats have their advantages and disadvantages. Want a small file-size photo? Use JPEG. Want transparent images? Use PNG. Want animation? Use GIF. Want a small file-size animated photographic image with transparency? That's a problem...
Google have unified all of these options so that WebP can be used for any kind of image. The latest Google announcement and WebP gallery shows some impressive statistics too. WebP shows, "...25-24% better compression compared to JPEG images" and an average file-size reduction of 45% compared to normal PNG images (28% better than optimised PNGs).
While most of us have broadband connections these days, this might not seem like a big deal. But with many aspects of computing, less is more – if a site can effectively use 100 PNGs on a page without losing performance, they could in theory use 120-150 WebPs. Also, as compression is better with WebP, images can be shown at a higher resolution and better quality whilst maintaining the original file-size.