Beginner’s Guide to Improving Page Speed When Using AddThis


Something that is often overlooked in any kind of web development is performance. The amount of time it takes from a user first navigating to your site until your site is drawn on their monitor has been proven to directly impact bounce rates, and de-prioritize your site in Google search results. At AddThis, we have a responsibility to provide you with the best tools the web has to offer, which includes keeping your page as fast as possible. In the past few weeks, we have made some big changes to keep your site snappy.

Measuring Your Site’s Performance

If you are not yet familiar with Google’s PageSpeed Insights, it’s time to get caught up. In a nutshell, PageSpeed Insights lets us get a view into any website’s loading performance, and provides suggestions for improving your score.

What’s New From AddThis

A few weeks ago, we to addressed two of the biggest complaints related to PageSpeed scores: removing render-blocking javascript, and removing render-blocking CSS.

Removing Render-blocking Javascript

If you haven’t looked at the Get the Code modal in the AddThis dashboard in a while, you’ll notice something new: our script tag has a fancy HTML async attribute on it. This tells modern browsers to hold off on running the javascript until your content has rendered. We also recommend including the script tag right before your closing body tag, which has a similar effect on older browsers which don’t understand async.

Check your own site to see if your AddThis script tag the async attribute. If it doesn’t, add it yourself by referencing the Get the Code modal in the dashboard.

Removing Render-blocking CSS

This suggestion appears in PageSpeed when your site is waiting on external style sheets before it can render your above-the-fold content. This can be tricky to diagnose and fix correctly. All AddThis users’ code has been upgraded to help address this issue automatically (at least for AddThis style sheets). If you’re interested in the technical details, you can check out our engineering blog post on the matter.

What’s Next?

Even if all of your AddThis-related PageSpeed issues have been resolved, chances are you will have others! Ask in the comments for help diagnosing issues on your site, or help others who’s issues you’ve come across before.