Google webmaster tools has added a new feature that will help webmasters you are ensuring their sites are mobile friendly prior to April 21.

One of the issues that can cause the site to not be mobile friendly is when webmasters block elements on the page from being crawled, commonly JavaScript and CSS. And sometimes those on the SEO team might not realize that the developers have blocked these elements from being crawled.

It is important for webmasters to unblock elements including JavaScript and CSS because without its, and Google is unable to determine for certain whether a site is genuinely mobile friendly or not.  And this will be an important aspect of the new Google mobile ranking change that comes into effect next month.

This new tool in Google Webmaster Tools will help alleviate this problem as this report will detail what is being blocked from Googlebot.

They also recommend that you check all variants of your sites including both www and non-www as well as HTTP and HTTPS for those with secure sites.

There are some reports that this new report is not updating very quickly, as some were saying the dates the elements had been checked back several months, even though the report is dated today.  So you could discover some resources are reporting that they are blocked, even if you have since unblocked them, or new elements might not show up yet.

And this will be an important aspect of the new Google mobile ranking change that comes into effect next month.