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.

  • Jake

    Personally, I prefer Chrome’s dev tools. The Audits provide page-speed light insights, and the timeline lets you get down in the dirt and identify what’s really going on when your page is loaded. They have good docs, too:

  • Currently there isn’t a way for you set the expiration date for these resources on your end. This is something though that’s been flagged for our developers and they’re looking into it.

  • Vern

    Any idea when this could be implemented?

  • Hi Vern, we don’t have a date for this at the moment.

  • Courtney Tucker

    I don’t see the html async tag in my AddThis code. How and where do I add it?

  • donald morrison

    Hello. Do you have any news about Leverage browser caching for addthis? We are working hard to get excellent google page speed insights but so far only the addthis making a little bit issues

  • Hi Courtney, apologies for the late response. Please email us at help [at] addthis [dot] com and our support team can assist.

  • Due to how we push out new releases, we don’t currently have a way to set an expiration for that asset. We’re looking into alternatives we can use for the future.

  • Firat Sekerli

    Is there any news about this? After adding AddThis to my website, my score went down 1 percent. Not a big deal, but still I would like to see this feature.

    Also, maybe it is not the place to ask, but on mobile, when I click share button, it opens a new browser window for Facebook. Is there a way to open the Facebook app? Because no one uses Facebook on browsers on mobile.


  • Ramsz

    Could you inform us about the progress that has been made in 1 year? Thank you.