What is Defer Parsing of javascript?
It is an important step to improving page load times and more importantly the time it takes to display the page on initial load. In order to load a page, the browser must parse the contents of all <script> tags, which adds additional time to the page load. By minimizing the amount of JavaScript needed to render the page, and deferring parsing of unneeded JavaScript until it needs to be executed, you can reduce the initial load time of your page.
I noticed this while running PageSpeed Insights on my blog recently and noticed some suggestions provided by PageSpeed. As you can see in below image I saw lots of JavaScript load script coming from “s-static.ak.fbcdn.net/rsrc.php“.
Now the main question: Where is all of these facebook code coming from?
While debugging further I found the culprit code of Facebook Like box Widget. I was using IFRAME code and then I switched to HTML5 code and this issue got resolved.
Look at this Pagespeed Insight again:
Here are the steps to fix this problem:
Step-1.
Get Facebook Likebox HTML5 code (section 1).
Step-2.
Put this code just before </body> tag. I’m using my own plugin “All in One Webmaster” to put this code in footer section.
Step-3.
Place the code for your plugin wherever you want the plugin to appear on your page (section 2).
And you are all set. Now your page should load lot faster and your PageSpeed score should increase too. Hope this helps you fix load time issue.