Web search colossal Google has urged website developers to make use of Chrome's new Page Visibility API to trim down their sites' activities when they are not being viewed by surfers.

The Page Visibility API lets sites to find out when web users are actually viewing them or when they are just sitting in a background tab. It also makes it possible to know when a website has been pre-rendered by Chrome's new Instant Pages tool.

Google’s recently announced feature, called Instant Pages, try to predict what Google search result a user is going to click on and then the search engine pre-renders the page before the user actually clicks.

Google engineering Mike Belshe said, “We all build our webpages on our own, and we try to take the resources that we need to run our webpages. And that's what we should be doing. When we're in the background, if we can recognize that other pages are running too and knock our own stuff down, that's really the way to go.”

There may be cases where the prediction about what the user wants to click on may go wrong, and the Page Visability API lets webmasters to spot such false traffic.

Currently available in the developer version of Chrome, Page Visibility API will be available in beta in a round a week’s time.