Ecommerce Site Structure: How to Plan Categories for SEO

This guide shows you how to plan an ecommerce site structure that works for shoppers and search engines: how to group categories, how deep the hierarchy should go, and how URLs and internal links should support it.

What is the best site structure for an ecommerce website?

The best structure for most online stores is a shallow hierarchy: homepage, main categories, subcategories where needed, then products, connected by crawlable links at every step. Google’s guide to ecommerce site structure describes the same chain: links from menus to category pages, from category pages to subcategory pages, and on to product pages.

Two points from that guide shape everything else. First, Google relies mainly on links, not URL patterns, to understand a site, and it states that it generally does not look at the structure of URLs to work out the structure of a site. Second, it uses the number of links needed to reach a page, and the number of links pointing to it, to estimate the page’s relative importance.

In practice that means your menus, category pages, breadcrumbs and related product links are your site structure. URLs matter for clarity and consistency, but the links decide what Google sees as important.

Google’s guide also points out two discovery gaps that matter for structure. If category pages do not link directly to all products in a category, Googlebot might miss some of them, and Googlebot generally does not submit searches into a search box, so products reachable only through internal search may stay undiscovered. Where you cannot link to every page, Google suggests providing a sitemap or a Merchant Center feed as a fallback.

How do I plan ecommerce categories from scratch?

Plan categories by grouping products the way customers search and shop, then checking each group against keyword data before you build it. Starting from your supplier’s catalog structure or internal product codes almost always produces categories nobody searches for.

1. List every product type you sell. Use plain names customers would say, such as “bar stools”, not internal names like “seating range B”.
2. Collect search terms for each type. Use a keyword tool and Search Console data to see which terms have demand, including modifiers like material, room or use.
3. Group terms into categories. Terms that a single product range can satisfy belong together. “Bar stools” and “kitchen bar stools” can share a category; “outdoor bar stools” may justify a subcategory.
4. Decide category versus filter. A modifier with real search demand and enough products becomes a subcategory. A modifier without demand stays a filter.
5. Sketch the tree. Draw homepage, categories and subcategories. Count products in each node; very small nodes are candidates for merging.
6. Check the menu. Main categories go in the main navigation. If the menu becomes overwhelming, the tree is too wide.

This decision table helps with step four, which is where most structures go wrong.

Filters that stay filters need their own crawl rules, which I cover in the technical SEO work on faceted navigation.

How many levels deep should ecommerce categories go?

Most stores work best with two levels of categories, a main category and a subcategory, and only large catalogs need a third. Google does not publish a maximum depth, but its site structure guide does say that the number of links needed to reach a page is one signal of how important that page is.

Depth in the category tree is not the same as click depth. A product four levels down in the hierarchy can still be two clicks from the homepage if it is linked from a “best sellers” block or a featured category. Google’s guide suggests linking top selling products from the homepage or from other content such as blog posts, to signal their importance.

Warning signs that your structure is too deep:

• Subcategories with only a handful of products.
• Breadcrumbs with five or more steps.
• Menus that require several hovers to reach a category people search for directly.
• Products that Search Console lists under “Discovered, currently not indexed” in large numbers.

That last sign often means Google has found URLs but not prioritised them, which can be linked to weak internal linking. My guide to discovered, currently not indexed explains the other causes to rule out.

Should product URLs include the category?

Product URLs usually should not include the category, because products often sit in several categories and categories change over time, while a short, flat product URL stays stable. Google’s ecommerce URL structure guidance uses /product/black-t-shirt-with-a-white-collar as its example: descriptive words, no category path.

Category based product URLs create two risks. A product in three categories can end up with three URLs, which is a duplicate content problem, and renaming or moving a category forces a redirect for every product inside it. Flat URLs avoid both.

Category URLs, on the other hand, can reflect the hierarchy, such as /sofas/corner-sofas/, because they are the hierarchy. Whatever pattern you choose, Google recommends using the same URL form consistently in internal links, sitemaps and canonical tags, giving every paginated page a unique URL, and avoiding temporary parameters such as session IDs.

One practical tip from migrations I have worked on: keep the product slug itself as close to the original as possible when you remove category folders. Moving from /sofas/leather/chesterfield-3-seater to /product/chesterfield-3-seater keeps the descriptive part identical, which makes the redirect map simple to build and easy to check. Test a sample of old URLs after launch to confirm each one returns a single 301 to its new address, with no chains.

What does a planned structure look like for a real store?

Changing URLs on an existing store is a migration, so plan the redirect map before you touch anything; my website redesign service is built around keeping rankings through changes like this. If you are planning categories for a new or existing store, the e-commerce SEO service includes category and structure planning from keyword research to menu design.

Frequently asked questions