Does your site rank better or worse based on which browser someone is using when they search in Google?  Do algos impact sites differently in different browsers?  What about mobile browsers?  Or does Google not take browser differences into account when deciding to rank sites.

The question came up in the most recent Google Webmaster Office Hours.

As far as I know, we don’t do anything specific in that regard.  So it’s not that we’ll say oh we’ll look at this page in Firefox or Internet Explorer and Chrome and look at them individually.  Essentially our algorithms look at pages as they are rendered in Googlebot, and use that as a basis.

The one thing that is kind of separate from this is the mobile site, where we look at the desktop view and mobile view separately.  But we don’t look into different browser types to see what different browser types would see.

That said, there have been times where SEOs have done identical searches via two different browsers, such as Chrome versus Firefox, and seen two different result sets for the same query.  But this is generally believed to be simply different datacenters being queried that have slightly different results as algos are updated and pages are being recrawled, or one is seeing a test that the other isn’t.  Personalization could also impact results, since it isn’t uncommon for someone to be logged into one browser but not the other.

And of course, Mueller mentions the mobile issue which is a caveat to this browser type and rankings issue.  Sites can rank differently based on mobile versus desktop.  So in this regards, you can see different results on a mobile browser when you compare it to a desktop.  But this is not specific to the specific browser used, but rather if you are viewing mobile results on a mobile device or desktop results on a desktop or laptop computer.