A question that is often asked is “Does changing the WordPress theme affect search engine rankings?” Many people find that their ranking changes when they change their WordPress theme, but this could be for a number of reasons unconnected with the theme itself.
A new theme in itself will not make any different to your rankings, but it may if that theme presents your data in a different way or in a different order in your HTML, even though it appears to be the same on the page. There is more to blog SEO than just the visible text. Here are some ways in which your rankings can drop when you change your blog theme.
The Order of Your HTML is Important
Search engines such as Google read your HTML in a linear manner. This might not be in the same order as it is presented on the screen. Content boxes and tables can be used to present your content in a different order to how the HTML expresses the page source code.
If you change a theme with a right hand sidebar with one with a left hand sidebar, the spiders will usually see the sidebar content before the main text. This will likely affect your ranking. With any theme, it is important to view the order of the page coding on your browser. Resolve your Home page or post, right click and click ‘View Page Source.’ Then make sure that the HTML in the Body section shows your main text first, before the sidebar content.
Algorithms provide different weighting to your keywords or semantically related vocabulary according to where it is presented in your linear HTML. They read the text outside tables first, and then the text within tables in the order these tables are presented. The introductory text is given higher weighting than that close to the end, while keywords in the final paragraph also receive a high weighting.
To summarize, if your new theme changes the way your HTML is read by the search engine spiders, then your ranking position can also be affected.
The Meta data is extremely important to your search engine ranking. At the very least you should use the same SEO plugins on your blog. If you used Yoast WordPress SEO with your original theme, then make sure you also use Yoast with your new theme. By using the same plugins and widgets with the new as you did with the old, you can go a long way towards making sure the theme change does not affect your ranking position.
Check that the Meta description and Title tags are identical, and that all other Meta data provided in the head section of your HTML are the same. One change could conceivably have an effect on you listing position.
The permalinks are the URLs to your blog posts, in much the same way as the URL of a web page defines the location of that page on your website. If your permalinks are changed when you change the WordPress theme, then that will definitely affect your search engine rankings in a bad way.
It is very important that you make sure the permalinks in your new theme are exactly the same as those in your previous theme. Check them to make sure that the URLs lead to the same posts or pages as the old permalinks did. Other bloggers will use the permalink as a link back to your page, and you will use it as a link back from another web page on your site or in an email linking to your post.
If not, then Google will drop those posts and pages from the rankings for the search terms/keywords for which they have been listed. If you are unable to create the same permalinks with your new theme then at least make sure you generate a 301 redirect to the original permalink URL to avoid a 404 error.
Maintain All Existing Links
It is not only the permalink that is important. The Google algorithm that calculates your search engine rankings take all links in your blog post into account. Every link leaving your blog must be exactly same in the new theme as in the old. Tag links, for example, must be maintained, as should any links attached to the blogroll, archives, graphics and images.
It is important that when you make a change to your theme you check the entire linking structure to make sure that all the links still work. This includes not only the links in the body of the post or page, but also links in your sidebars, your widgets and any adverts you are running.
Miscellaneous Reasons for Ranking Changes
If the change of theme appears to have affected you search engine rankings, either positively or negatively, there might be yet other reasons for this. Take Adsense, for example. If you changed your Adsense block placements between the two themes, or even used more blocks in the new theme (say 3 rather than 2), this can affect your rankings.
Google might punish your page for having excessive adverts on a page in relation to the amount of text. It might even improve your ranking if your Adsense is more intelligently sited. There are over 200 factors taken into consideration in your listing position, and only Google knows what these all are.
Page Speed and Bounce Rate
The loading speed of you blog is also important. If your blog is loading too slowly in a visitor’s browser, they may simply leave rather than wait. Bounce rate is one of the factors involved in your ranking, so compare the loading speeds of the old and new theme. There are free tools like GTmetrix and PageSpeed Insights available online to enable you to do this.
If the HTML in the old theme has been W3C validated, and the HTML in the new theme has not been, then it is possible for this to lead to crawling errors. This in turn may result in loss in ranking.
If your new theme has been constructed using a shared mark-up vocabulary such as Schema.org, then you should experience an improvement in your listing. The Genesis WordPress framework is one example of this. If you choose any theme that positively affects the readability of your website by search engines, then you should see a jump in you rankings.
Because of this, the safest course is not to make any changes that affect your entire blog. If you must change your theme, select one that is a close variant of your existing theme. An example would be another of the WordPress themes, or a theme designed by the same company as your original.
If this is not possible, make as few other changes as you can – at least for a while. Once you are sure the theme has not changed you ranking, you can then begin making other changes one at a time, so you can identify the cause of any ranking loss.
So, does changing the WordPress theme affect search engine rankings? Yes, it can, but not always. If it does, look for an inherent change in your source code an in the way your post or page content is presented in the HTML.