Google has confirmed that their page speed update – officially called the “Speed Update” is now rolling out.  The change makes a site’s mobile page speed a ranking factor.

Google’s Page Speed Algo had previously only considered the desktop speed forsearch results, with sites with a very slow desktop speed being impacted negatively in both the desktop and mobile search results.  But this new change means that Google will use the mobile page speed instead of the desktop one for all mobile searches.

This will impact all mobile sites, even those that haven’t been officially moved over to mobile first indexing.  If your site is using AMP, and it is implemented correctly, then those pages will not be negatively impacted.

Google has said it is looking to target the slowest mobile sites.  Google has said that there is a “sliding scale” where sites can see improvements.  John Mueller stated that sites that are “reasonably fast” won’t see ranking improvements but “slowest sites” will.  But where that line between sites that will see improvement from small changes to speed and those that won’t are unclear.

Along those lines, Google won’t give us a number to focus on, because all speed tools use different metrics and Google would rather site owners focus improving sites for users, not Google.  He also said there isn’t “a single metric that covers everything relevant for speed.”

The mobile page speed update and the mobile first indexing are two independent things.  So the mobile page speed update will impact sites regardless of whether or not they have been moved to mobile first indexing or not.

Google says this will only impact a small percentage of searches, and that Google will continue to show brand sites for branded searches, regardless of the site’s mobile speed.  So even if a site is exceptionally slow, but the search is clearly looking for that site, Google will still show it in the search results.

This change is not surprising.  More searches on Google are done from a mobile device than a desktop one, yet many sites only focused on the desktop speed for SEO, and not the mobile speed, since that mobile speed did not impact Google rankings.