Google Web Light is a light-weight web page technology offered by Google, for people that still operate on slow connections (such as 2G or satellite). It does this by converting existing website data on the fly, so that the resulting website is optimised for slow connection speeds.
Here is how Google describes Google Web Light:
"To do this, we transcode (convert) web pages on the fly into a version optimized for slow networks, so that these pages load faster while saving data."
Google Web Light optimized pages load four times faster than the original page and use 80% fewer bytes. As a result, Google has seen a 50% increase in traffic to Web Light pages. You cannot create your own Web Light pages (unlike AMP), however you can preview what a Web Light page will look like. This is important from a Google Search Console perspective as far as impressions are concerned.
To preview a Web Light version of a non-AMP webpage, using your favourite browser, enter the following URL :
Perhaps the only concern with Google Web Light, is that there have been instances where it bypasses content filters. (See below.) Otherwise, it is a web technology most needed in countries that have slow internet connection speeds (such as Brazil, Philippines and India).
If you do not want to have your website trans-coded into Web Light, you can set the following HTTP header at the top of your webpage :
The next time Googlebot sees this HTTP header, your page won't be trans-coded.