Site Accelerator WebP Image Support

We’re happy to announce that the Site Accelerator (previously Photon)  image service now offers seamless support for the WebP image format. This new feature provides size reductions of up to 34% for served images compared to a JPEG of an equivalent visual quality level. One thing to keep in mind, though: WebP isn’t currently supported by all browsers (see the WebP FAQ for more details).

Image comparison - JPEG Image comparison - WebP
JPEG File Size – 43.84KB WebP File Size – 29.61KB

Visually identical images in JPEG and WebP format with their respective sizes.

The trick in serving a format that isn’t universally supported is to auto-detect which browsers do support it, a process that can become clunky and unwieldy. We found a simple solution, however, in the Accept header, which is sent along with every image request. In this header the browser specifies whether it supports the WebP image format. Consequently, when our regionally distributed Site Accelerator CDN servers analyze the headers, the service is able to detect and serve the best image format for each browser request that comes in from its local cache.

We should note that by default, Site Accelerator is compressing the WebP images at a high quality setting. If you want to get the most out of this new feature, utilizing the quality parameter will yield the best results.

Additional Resources: