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Website Themes Impact SEO

Google's John Mueller says that website themes impact SEO. Site design and SEO experts share what to know before choosing a website theme

Website Theme Impacts SEO

Google published a short video that answers if a website theme affects SEO. John Mueller, the video host, answered that yes, a website theme will affect SEO and noted how this can happen.

Mueller said:

“It’s easy to consider website themes as just a splash of color on top of a finished structure. But there’s so much more involved.”

A theme will impact how the website displays many content elements that are core to SEO:

  • Headings
  • Text
  • Images
  • How pages are interlinked
  • Page load times
  • Structured Data

According to Google, good themes will make it easier for search engines to understand the content and Mueller affirmed that changing a website’s theme generally will affect a website’s SEO.

Related: How to Choose the Best Shopify Theme for SEO

Test Drive New Website Themes

John Mueller said that it was a good idea to test out a website theme before choosing one.


  • Try themes out on a test website
  • Add content from previous website
  • Block indexing of a test website so that Google doesn’t accidentally crawl it
  • Review HTML generated by the theme

Insights From Search Community

I asked a few SEO and web design experts if they thought that the choice of a website theme affected SEO.

Adam J. Humphreys

Search marketing expert Adam J. Humphreys (LinkedIn profile) of Making 8 Inc shared his insights about how themes impact SEO:

“Yes, absolutely the way websites render impacts the way they resolve for search engines.

I saw a 26% increase to a large boat group’s overall views and their best year on record as a result of changes made to their themes.

Themes really matter and frankly, if using WordPress for example, one should use Gutenberg-based editors (otherwise known as Gutenberg blocks builders) for WordPress because they are the purest form of editor utilizing the WordPress core and will result in a ridiculously fast page speed.

The reality is even if Google’s Core Web Vitals wasn’t a ranking factor I would still make it a priority as I have for years simply because of how well users respond to fast sites. We’re talking more clicks, more calls, and generally speaking more sales conversions. Whether it’s a multinational level site or a local business, the positive response seems to be the same.

This is why I recommended Gutenberg Blocks based editors because they use the WordPress engine resulting in a much faster load time.

Oxygen and Bricks Builder this year are my only two recommendations on themes for those willing to take the time to learn them.

Otherwise just straight up WordPress editor because everything else will not accomplish 100 on mobile scores in a mobile first world.

Alternative themes load up too many scripts which is guaranteed to result in lower scores.

Less moving parts means less friction, which is the same for choosing a theme for SEO.”

Chris Labbate

Chris Labbate (LinkedIn profile), Director of Marketing at agreed that the choice of a theme was critical:

“Changing your WordPress theme can affect SEO rankings, to a significant degree if you make a poor choice.

One of the reasons is because your theme impacts your design (CSS and JavaScript) which in turn can affect site speed.”

Alex Alexakis

Alex Alexakis (LinkedIn profile), founder of PixelChefs offered his insightful opinion on the importance of themes to SEO:

“Yes, changing a site’s theme can affect a website’s speed as design, page structure, internal links and sometimes architecture changes.

For example, themes can negatively affect your sites speed by:

  • requiring multiple plugins to function “properly”
  • loading excess external resources (scripts, webfonts)
  • loading excess internal resources (scripts, webfonts)
  • poor coding
  • unoptimized css
  • unoptimized javascript / jquery

Site architecture is a big issue especially in site rebuilds as some themes are set up with custom built custom post types that force a URL structure that might not match the existing architecture.”

Choose Your Website Theme Carefully

Many themes advertise themselves as SEO friendly. But that’s not always the case. Many themes provide low performance scores in Google’s PageSpeed insights tool. Even the demonstration sites for some of the “SEO friendly” themes perform poorly.

Page Speed Score of an “SEO Friendly” Theme

Screenshot of poor performance scores of an "SEO friendly" themeThis is an actual PageSpeed Insights score of 35 out of 100 for a theme that advertises itself as SEO Friendly

Adam J. Humphrey is right to mention Gutenberg Block Editor as a viable option for building a fast performing website. Building directly with the WordPress Gutenberg site builder is faster because the site is generated straight from the core and does not have to go through any additional layers. WordPress has steadily been improving the Gutenberg code so that it only loads the files necessary to generate a web page.

It is important to understand that Gutenberg isn’t fully finished. It is being built in four phases and WordPress is currently well into the second phase that addresses bringing full site editing to Gutenberg.

Four Phases of Gutenberg Development

  1. Easier Editing — Already available in WordPress, with ongoing improvements
  2. Customization — Full Site editing, Block Patterns, Block Directory, Block based themes
  3. Collaboration — A more intuitive way to co-author content
  4. Multi-lingual — Core implementation for Multi-lingual sites

As John Mueller suggested, always set up a test site for staging your new WordPress theme where you can configure the site to be exactly how you want it to.

Services like WP Stagecoach, which I have used, make the process easy.


Watch the Google Video

Does a Website Theme Matter for SEO?

Category News SEO
SEJ STAFF Roger Montti Owner - at

I have 25 years hands-on experience in SEO and have kept on  top of the evolution of search every step ...

Website Themes Impact SEO

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