Site Architecture: Is it really necessary to choose between flat and deep?

Why does Google care about site architecture?

The architecture determines how Googlebot discovers and evaluates your pages. An overly flat structure — where all pages are accessible in one click from the homepage — drowns the crawler in an ocean of links at the same hierarchical level. The result: it's impossible to distinguish the strategic pages from the less important ones.

Conversely, an architecture that's too deep — where some content requires 5, 6 clicks or more — sends a clear signal: these pages are low priority. The crawl budget gets exhausted before reaching them, and even if indexed, they inherit a diluted authority due to the distance from root pages.

What does 'finding a balance' actually mean?

Mueller doesn't provide a magic number, and that's intentional. The balance depends on your business context, content volume, and editorial strategy. An e-commerce site with 10,000 products won't have the same architecture as a blog with 200 articles.

The idea is to structure by thematic clusters and ensure that every important page is accessible within 2-3 clicks maximum from the homepage. This requires consideration of depth levels, internal linking, and category hierarchy. The signal sent to Google should be consistent with your business priorities.

Does Google impose a limit on the number of products per category?

No, and this is reassuring for large catalogs. Mueller specifies that there are no strict rules regarding the number of products per category. A category can contain 50, 200, or 500 items if it's logical for the user and pagination or filtering are well managed.

The real criterion: navigability. If the user can find their way, if the crawl remains smooth, and if the relevance signals are clear, the absolute number matters little. What counts is the semantic coherence and technical accessibility.

• Flat Architecture: everything at the same level, dilution of authority, no hierarchical signal
• Deep Architecture: pages buried, slowed crawling, risk of partial or late indexing
• Balance: 2-3 clicks max for strategic pages, thematic clusters, optimized internal linking
• No strict limit on the number of products per category, as long as navigability and crawling remain smooth

Does this statement align with real-world practices?

Yes, and it confirms what SEO audits regularly reveal: high-performing sites have architecture designed like a decision tree, not like a flat list or a maze. The most strategic pages — those generating traffic, conversions, and authority — are quickly accessible and benefit from a reinforced internal linking.

Where it gets tricky: many CMS and e-commerce platforms default to creating structures that are too deep or, conversely, too flat. Teams find themselves suffering from a technical architecture that contradicts their editorial strategy. Mueller doesn't say it, but that's often where the battle is fought.

What nuances should be added to this rule?

First nuance: the number of clicks is not an absolute dogma. What matters is the internal PageRank, the hierarchy signals, and the crawler's ability to identify priorities. A page accessible in 4 clicks but massively linked from strategic hubs can easily outperform a page in 1 click but orphaned.

Second nuance: architectural depth is not always synonymous with crawl depth. If your XML sitemaps are well organized, if your internal linking compensates for depth levels, and if your pages are regularly updated, crawling remains smooth even on complex architectures. [To be verified] on a case-by-case basis, according to the actual crawl budget allocated to your domain.

In what cases does this rule not fully apply?

On high-volume sites — marketplaces, aggregators, public databases — the flat/deep balance becomes secondary compared to issues of crawl budget, deduplication, and facet filtering. These sites often need to sacrifice the accessibility of certain pages to avoid exhausting crawl on infinite filter combinations.

Another exception: low domain authority sites. If your crawl budget is limited, even a theoretically perfect architecture won't be sufficient — you'll first need to work on authority signals (backlinks, freshness, engagement) before architectural optimization can yield results. Let's be honest: architecture amplifies authority; it doesn't create it ex nihilo.

What practical steps should be taken to rebalance your architecture?

Start with a full crawl of your site using Screaming Frog or Botify. Identify the depth of each URL and cross-reference with Analytics data: which strategic pages are buried 4, 5 clicks or more deep? Which categories are overloaded with products to the point of creating infinite pagination pages?

Next, restructure by thematic clusters. Group content by search intent, not CMS logic. Priority pages — those that convert, those that already rank, those that reflect your positioning — should be accessible within 2-3 clicks maximum from the homepage. The rest can drop a level, as long as a consistent internal linking is maintained.

What mistakes should be avoided during architecture redesign?

Don't confuse SEO architecture with visual hierarchy. What the user sees in the menu is not necessarily what Googlebot sees in the HTML code. Mega menus in JavaScript, hidden links in lazy load, infinite facets — all can distort the perception of depth.

Avoid also bringing everything up to level 1 under the guise of accessibility. A page that has no legitimacy to be at the top of the hierarchy will send an inconsistent signal. The balance is exactly that: to prioritize according to business value and semantic relevance, not according to a mechanical rule.

How can I check if my architecture is optimized for Google?

Inspect the internal PageRank distribution using a tool like OnCrawl or Oncrawl. If your strategic pages are capturing less juice than auxiliary pages, it’s a sign of imbalance. Also check the server logs: which pages does Googlebot visit first? How much time does it spend at each depth level?

Finally, compare the indexing coverage in the Search Console with your actual page inventory. If entire categories are discovered but not indexed, it indicates that the architecture isn't transmitting enough priority signals. This is reversible, but it requires effort.

• Crawl the site and map the depth of each URL
• Identify strategic pages buried more than 3 clicks deep
• Restructure by thematic clusters and search intentions
• Optimize internal linking to compensate for residual depth
• Check internal PageRank distribution with a dedicated tool
• Analyze server logs to ensure Googlebot follows the new hierarchy