Page depth refers to the number of clicks you need to reach a specific page from the highest point in your site structure using the shortest path. A page directly linked to from the highest point is at depth 2 (the initial page itself is always 1!).
Often, we think of this highest point or initial page as the home page. When crawling, though, it is always your Start URL. Any Start URLs in your crawl settings will have a depth of 1. Any page linked to from your Start URLs will have a depth of 2, and so on. This is one reason we recommend crawling at least occasionally using your home page as your Start URL.
If a page needs more than 3 clicks to be reached, it will often perform poorly. The deeper a page is in your site architecture, the more you signal to search engines that it isn't important.
In fact, search engines are less likely to find and to crawl deep pages. If a page is hard to find, crawlers won’t check them as often as pages at higher depths, which lowers their chances to be ranked.
Deep pages are often visited less often by users, as well. On some sites, pages that haven't been visited recently by bots or by users will no longer be cached, which means that their page speed will also be slower.
Websites need to be thought in terms of the depth of their pages. Pay attention to page depth distribution because it offers an overview of the overall structure of the site and of pages performing badly.
Best practices to page depth
Use your internal linking
If you own a large website with a lot of deep pages, reorganizing your internal structure manually could be a nightmare. If you do not want to start again from scratch, you can lower your site’s depth through the help of internal linking, using external backlinks and internal backlinks. It has the advantage to:
Lower the number of clicks needed to reach a page on your website and to facilitate the crawler’s job
Increase your user experience by providing visitors additional valuable content
Lower your bounce rate since users will have a better access to the information they are looking for
Every time you create a new blog post for example, check if there is any opportunity to link to something relevant you have already written on your website. You can then create an internal link. But be careful, you should only link to something useful and avoid stuffing keyword strategies on anchor-text.
Breadcrumbs will make it easier for your visitors to know where they are on your website. Categories are essential to organize your site but do not overuse subcategories because it will certainly take more than 3 clicks to get there. To know more about breadcrumbs you can check our article.