The majority of modern webpages today don’t just get content from their own server but also load numerous scripts for ads, analytics and other features like the ubiquitous Facebook like buttons from across the web. Often, loading these scripts from third-party services can take a while and browsers often have to wait for these services to respond before they can continue to load a site. This means a site’s visitors will have to wait longer before they actually get to see the content they originally visited a site for.
To get around these roadblocks, many modern scripts now load asynchronously – meaning the rest of the page can be displayed even if your Twitter share button is still waiting to hear back from its own servers. Google today announced that its online advertising program AdSense, which according to Google is used by more than two million publishers now loads its ads asynchronously. This change, says Google, “is now making billions of web pages every day load faster by half a second or more.”
Website owners who already run AdSense ads won’t have to do anything to get the benefits of this improved ad delivery mechanism. Because of the way Google has implemented this, though (with “dynamically-populated friendly iframes”), the faster ads will currently only work in Chrome, Firefox and Internet Explorer 9. Google plans to support other browsers in the near future.