Can a Website’s Theme Affect Its SEO? Google Says, “Yes.”

The WordPress theme you select can make a difference to your site’s SEO performance. A Google employee gives examples.
SIA Team
September 15, 2021

Yesterday, September 14th, 2021, Google added a new video to its #AskGooglebot video series, which is basically a YouTube playlist of short videos

In each video, John Mueller, who’s a Search Advocate at Google, answers a specific question about a topic that’s relevant to webmasters and SEO professionals. 

In yesterday’s video, there were 3 related questions, all having to do with how a WordPress site’s theme can play a role in SEO. 

The questions were: 

Does changing the theme of a WordPress website affect the ranking?

If it does, to what degree?  

What are the best practices while changing the theme/design? 

To begin, yes, changing the theme of a WordPress website can affect various aspects of its SEO performance, and hence, ranking. 

More specifically, themes can differ from each other in the sense that a new theme can be different in how content is displayed, whether or not there are internal links, whether the page loads quicker or slower, what the content options are, and structured data use. (Changing to a new theme can affect more than just those.)

The Degree to Which Ranking/SEO Can Be Affected

As to what degree, well…it depends, of course on the theme you’re switching from, and the theme you’re switching to. (On some themes, even a change to a certain setting plugin can make a difference in SEO performance.)

Best Practices While Changing Themes

One thing that John recommends is that, before launching, or re-launching, with a new theme, you test your prospective/new theme on a practice website. He advises blocking robots (I’m guessing in robots.txt) so that your test website isn’t crawled. 

(Personally, what I might do is just create a subdomain or subdirectory, install WordPress, and then, add my new theme to that new WordPress installation.)

Alternatively, instead of creating a new site, subdomain, or subdirectory, you can just install the theme onto your current WordPress site, and then test your new theme on the live site. The only small concern is that something may go wrong, but if that’s the case, you can always quickly switch back to your previous theme. 

Do Consider How Your Content Is Displayed

John suggests checking out the SEO Starter Guide, and also to consider the HTML that’s generated by the theme. 

You can also use testing tools in Search Console to test your prospective theme, and make comparisons to your current one. 

One such test (though it’s not in Search Console), is Google’s Page Speed Insights. You can basically open Page Speed Insights in two different tabs, put the URL of your current theme into one tab, run the test, and compare your score with the URL of your test site/prospective them in the second tab.

(Other speed tests that I like are GTMetrix and Pingdom Tools’ Website Speed Test.) 

Most modern WordPress themes are Mobile-Friendly (which means they’ll display well on a mobile device), but just to be sure, you can test it out using Google’s Mobile-Friendly test

On YouTube, one of the links in the video’s description area goes to this debugging page, so depending on your situation, time, and resources, do check it out (or have your webmaster do so).

What’s been covered here (and in the video) are just the beginning of what can be an extensive discussion. That said, if you diligently apply the testing methods listed here, you can go a long way in determining if your prospective theme will be an SEO advantage to you.

That said, do remember something that’s, in some ways, more important than SEO and, in a way, determines SEO, and that’s UX, or user experience. 

Google’s SEO is based on how they think users like your pages. 

Great, helpful, one-of-a-kind quality content that’s easy to access is probably just as important as the theme you use. And, if the theme you use enhances UX while having great SEO performance metrics, you’ve got a winning candidate.

Source: Google Search Central YouTube channel