John Mueller, expert for SEO and search engine optimization at Google, has assured in one of his regular conversations with users that it is possible to change the template of a website affect your positioningeven if no URL or its content is changed.
Changing the template and design can affect a webpage beyond what is visible and change its position on Google
During “Google Office Hours”, a Hangouts show in which John Mueller answers questions from users, a viewer asked if a change in the design of a website could affect the Google ranking. Mueller’s answer was straightforward: yes, the change may affect your position on the Google results page.
That statement is surprising since On the surface, the design changes are only visual. However, according to Mueller, templates and layouts contain HTML and CSS elements that cause parts of the content to change slightly. For example, it is common for even “SEO friendly” templates to change the way that SEO elements such as headings and subtitles are displayed.
On the other hand, these changes can also have a positive effect. For example, a template that contains less HTML and Java code is lighter and therefore the web page loads much faster. Google will understand that this page meets the user experience requirements and will therefore position it better.
Whenever you change the template of a webpage, the best thing to do is to verify that all of the elements are working properly. With that in mind, the default images should be changed to reduce their weight, adjust their size, and adjust any button to match the style of the page. The design of the template should also be intuitive and easy to navigate for the best possible user experience on the page.
Here is the video from “Google Office Hours” where Miller explains the problem with the template change: