Definition
Crawl depth (or click depth) is the minimum number of internal links a crawler must follow from the homepage to reach a given page. Pages at depth 1–2 (linked from homepage or one-click-from-homepage) get crawled most often. Depth 3–4 sees slower refresh. Depth 5+ may be missed entirely by AI crawlers with smaller crawl budgets.
Homepage → /blog → /blog/category → /blog/category/post-2 = depth 3. Homepage → /featured-pillar-post = depth 1. The pillar gets crawled 10x more often.
How to optimize
Surface important pages from homepage or category landing pages. Don't bury content behind 4+ clicks of pagination. Use breadcrumb navigation for clarity.