To determine whether a page is mobile-friendly, Google uses a set of criteria that includes things like the size of the text and images, the layout of the page, and the presence of buttons and links that are easy to click on a mobile device. If a page meets these criteria, it will be considered mobile-friendly and will not be affected by the update.
However, if a page does not meet these criteria, it will be considered not mobile-friendly and will see a decrease in ranking on mobile search results. This means that if a website has some pages that are mobile-friendly and some that are not, only the non-mobile-friendly pages will be affected by the update.
It's worth noting that the Mobile-Friendly Update only affects mobile search results, not desktop search results. This means that if a page is not mobile-friendly, it will only see a decrease in ranking on mobile search results, not on desktop search results.
So, to answer the question of whether the Mobile-Friendly Update will affect all pages on a website or just certain ones, the answer is that it will only affect certain pages – specifically, those that are not mobile-friendly.
However, it's important to note that the Mobile-Friendly Update is just one of many factors that Google takes into consideration when ranking websites in search results. There are many other factors that can affect a website's ranking, such as the quality and relevance of the content, the presence of backlinks, and the overall user experience.
Therefore, it's important for website owners to not only make sure that their pages are mobile-friendly, but also to focus on these other ranking factors in order to improve their overall search rankings.
One way to do this is to regularly update the content on a website with high-quality, relevant information that is valuable to users. This can help to attract backlinks, which are links from other websites that point to a website, and can also help to improve the overall user experience.
Another way to improve search rankings is to make sure that a website is easy to navigate and that it has a clean, user-friendly design. This can help to improve the overall user experience and can also help to increase the chances that users will spend more time on the website, which can in turn lead to a higher ranking in search results.
Finally, it's important for website owners to regularly check their website's mobile-friendliness and to make any necessary updates in order to ensure that they are meeting Google's criteria for mobile-friendliness. This can help to ensure that their pages are not affected by the Mobile-Friendly Update and can help to improve their overall search rankings on mobile devices.