Google Search Console has begun showing site owners how often Web Light search results are served to users.
Here’s how Google describes the process of converting regular pages into Web Light pages: “we transcodified (convert) web pages on the fly into a version optimized for slow networks, so that these pages load faster while saving data.”

Web Light pages retain most of the relevant content contained on a page, and also offers users a link to view the original page.

Google says Web Light optimized web pages load four times faster than the original page and use 80% fewer bytes. As a result of how fast these pages load, Google has seen a 50% increase in traffic to Web Light pages. Web Light pages are faster and lighter than AMP pages. In fact, AMP pages may even be modified into Web Light pages to further reducing loading time. Google says modifications include font and image optimization.

Unlike AMP, site owners cannot create their own Web Light pages. They can, however, see what regular pages look like as a Web Light page. This may be important to pay attention to if Search Console shows that Web Light pages account for a significant number of impressions.

If you do not want your websites to be transcoded into Web Light, set the HTTP header “Cache-Control: no-transform” in your page response. If Googlebot sees this header, your page will not be transcoded.

credits: Search Engine Journal