Crawl depth

What is crawl depth?

Crawl depth, also called click depth, is the number of links a crawler has to follow from the homepage, or another start page, to reach a page. The homepage has a depth of 0, pages linked from it have a depth of 1, and so on. It measures how buried a page is in a site’s link structure.

Depth is about the shortest path through links, not the folder structure of the URL. /products/shoes/trainers/red-trainers can sit at depth 1 if it is linked from the homepage, and /red-trainers can sit at depth 6 if it is only reachable through pagination.

Why crawl depth matters for SEO

Search engines find most pages through links, and pages close to the homepage tend to be crawled more often and seen as more important. A page ten clicks deep is likely to be crawled rarely, and it receives little link equity from the rest of the site.

A common rule of thumb is to keep important pages within about three clicks of the homepage. It is a guideline, not a Google rule, but deep pages are a reliable symptom of weak site architecture, long pagination chains or missing category links.

How to reduce crawl depth

1. Crawl the site and sort pages by depth. Look for important pages beyond three or four clicks.
2. Add links from category and hub pages, and use related-content and related-product links between pages at the same level.
3. Flatten deep pagination by showing more items per page or linking to more page numbers at once.
4. Add breadcrumbs and, on very large sites, an HTML sitemap.
5. Do not rely on the XML sitemap alone. It helps discovery but adds no internal links.

Crawl depth example

Homepage (depth 0) → Shoes category (1) → Trainers subcategory (2) → Page 4 of trainers (5, after following pages 2 and 3) → Red trainers product (6). Linking Red trainers from the Trainers category’s featured list brings it to depth 3.