According to Google Webmaster Trends Analyst Gary Illyes, the mobile-first index has started to slowly roll out, at least for a “few sites,” he said to an audience during the SMX East conference in New York City.

Right now, it’s unclear how many sites of been switched over to the mobile-first indexing process.  When asked to clarify what he meant by “a few sites,” he said a few relative to the Google index.  This could be a large number of websites.

Illyes said that there isn’t any reason to panic about the rollout, as Google is still testing it, and will be rolling it out slowly.  What’s more, he said that there isn’t any foreseeable time when the mobile-first index will be fully implemented.

This is a bit surprising, as it wasn’t expected to rollout until next year.  This is still positive, as Google has been encouraged by the positive test results.

When it comes to selecting sites to switch over, Google set up “classifiers” that will define how ready a site is for the mobile-first index.  Classifiers will determine how equal or comparable the desktop site is to the mobile site when it comes to things like links, multimedia, schema, and the like.

If the content, schema and links and all that math at 100 percent, Google is more likely to take that site to the mobile-first indexing stage.  If its at an 80 percent level, Google might decide to wait and communicate to the webmaster that there are some changes that have to be made to the mobile site in order to get it closer to being 100 percent comparable.

Gary Illyes said that the purpose of doing a limited roll out is to test it more.  So far, the tests are going well, and because of this, more sites will get the mobile index treatment slowly over time.  As stated multiple times, the rollout will be incredibly slow, and during this time, Google will communicate the process to webmasters along the way.

Currently, Google has a blog post int he works, and it’ll be published at some point, with the focus on helping webmasters and SEOs understand the process.  The company isn’t providing a timeline or ETA for the rollout or the blog post.  But it’s been confirmed that they’re on the way.

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