Added: We have an updated guide Everything You Need to Know About the Mobile Friendly Algo, which is updated with this information and more.

At SMX West today, Gary Illyes was put on the hot seat by SEOs and moderator Barry Schwartz on the upcoming mobile changes to Google’s ranking algorithm for searchers on mobile devices.  Here is what we learned.

Responsive does not have a ranking benefit

Because Google has been pushing responsive design as a way to handle mobile traffic, some people wondered if the only solution was to also use responsive because it could give a rankings boost.  However, Gary Illyes says that they recommended it because it worked well for Google, so they believed that solution would work for almost everyone.  That said, webmasters do not have to use responsive for mobile, as other mobile site choices work just as well.  He reiterated that responsive design does not have a ranking benefit.

Your site must unblock CSS & javascript

If you are blocking elements such as CSS and javascript, your site will not pass Google’s mobile friendly test, even if everything else on the site passes.  So you do need to allow Googlebot to crawl both CSS & javascript to pass.

Mobile friendliness is page by page

When determining if a page is mobile friendly, Google bases this on a page by page case.  So passing some pages, or even most pages, as mobile friendly will not mean your entire site passes the check.  All pages must be mobile friendly.

Will there be a specific tablet only ranking factor for those using tablets?

According to Gary Illyes, Google does not have any plans at this time to have anything specific for tablet rankings.

Will this change go live on April 21st or is there wiggle room?

Illyes would not comment much on this, other than “I will say April 21st is a very important day.”

Is there a cut off date when sites need to be mobile ready for?

He wouldn’t say if there was a delay between getting a site mobile friendly and when it will rank accordingly, he did say to just “have them ready by the 21st and it will be good.”

How long is the delay between making it mobile friendly and it being reflected in the search results?

Illyes says “As soon as we discover it is mobile friendly, on a URL by URL basis, it will be updated.

Will Google also release another update  such as Penguin or Panda on the same day to confuse webmasters?

Illyes said “I’m not aware of anything else that is changing on that day.”  That said, things could change between now and then.

Is there any possibility of this change impacting desktop?

Illyes says that “to the best of my knowledge, no.”  Of course, webmasters will take that as you will.

Is Google considering a completely separate mobile index in the future?

Illyes dropped a bit of a bombshell by saying that Google already has plans for this and there is a team already working on it.  He isn’t sure what stage they are at, so Google has nothing to announce about it at this time.  (More here: Google is Working on Completely Separate Mobile Index From Desktop Index)

Google doesn’t need to see noscript if they can crawl it

Many webmasters used noscript when javascript was not executed for whatever reason.  But Illyes says that Google still sees noscript, but cancel it out when they crawl the javascript.

What about offsite resources that may block javascript?

Because webmasters don’t always have control of offsite javascript – for example Google Analytics code – so Google takes this into account.  But Illyes does stress again that webmasters need to allow Googlebot to crawl javascript and CSS on their website itself.

For more coverage on the mobile changes: Google’s Mobile Ranking Boost Will Be Stronger Than HTTPS Ranking Boost; Google is Working on Completely Separate Mobile Index From Desktop Index; Google Mobile Friendly Ranking Signal Affects Non-English Search Results Too

Photo credit: Steve Boymel