What Is URL Structure?

How URL Structure Works

Every URL is read twice: once by a person deciding whether to click, and once by a crawler deciding what the page is about and whether it duplicates something it has already seen. Good URL structure serves both readers at the same time. A URL like https://example.com/summer-clothing/dresses announces its contents and its place in the site’s hierarchy in a way that a string of numbers and query variables never can.

Google’s URL structure documentation is unusually direct about what it wants. It recommends “readable words rather than long ID numbers,” contrasting the clean https://example.com/wiki/Aviation with the opaque https://example.com/index.php?topic=42&area=3a5ebc944f41daa6f849f730f1. The first is a URL a human could type from memory; the second is machine exhaust.

The address also encodes hierarchy. Path segments separated by slashes imply a tree of sections and subsections, and that tree overlaps with your site architecture and the internal links that connect it. When the folder structure is logical, both users and crawlers can reason about where a page sits and what its siblings might be — the difference between a filing cabinet and a pile.

Components of a URL

A modern URL breaks into predictable parts, and structure decisions live in each one:

• Scheme — https://, which should be HTTPS on every production page.
• Host — the domain and any subdomain, such as www.example.com.
• Path — the folder-and-file segments (/summer-clothing/dresses), where the slug is usually the final human-readable segment.
• Separators — Google recommends hyphens between words, not underscores: summer-clothing, never summer_clothing, because hyphens help identify concepts.
• Parameters — the optional query string after a ?, made of one or more URL parameters like ?color=grey. These are the part most likely to spiral into duplication.

Encoding and Localization

For non-English audiences, Google advises using “words in your audience’s language in the URL,” transliterated where appropriate, and percent-encoding any non-ASCII characters. The docs show the German word gemüse written as https://example.com/gem%C3%BCse, and the Arabic and Chinese equivalents encoded the same way. Browsers still render these readably to the user while keeping the raw URL valid. For multi-regional sites, Google names two clean patterns: a country-specific domain such as https://example.de, or a country subdirectory on a generic domain such as https://example.com/de/.

Example of URL Structure

Google’s own documentation supplies the clearest worked comparison, because it states the preference and the counterexample side by side. In the “Keep a simple URL structure” guidance, the recommended form for a filtered category page is:

https://example.com/summer-clothing/filter?color-profile=dark-grey

and the form to avoid is:

https://example.com/summer_clothing/filter?color_profile=dark_grey

The two URLs point at the same conceptual page. The only differences are the separators — hyphens versus underscores inside the words. Google’s stated reason is specific: hyphens “help users and search engines better identify concepts” in the address, so dark-grey reads as two words while dark_grey risks reading as one token.

The document pairs this with its readability rule, preferring https://example.com/wiki/Aviation over an ID-driven index.php?topic=42&area=... address that carries the same content. Held together, these examples describe a single principle: the URL should be the shortest honest description of the page, spelled in words a person can read, joined by hyphens, and arranged in a hierarchy that mirrors how the content is organized. None of this is a strong ranking lever on its own — Google is careful never to promise that. It is a clarity and stability discipline that pays off across crawling, canonicalization, and every human who has to trust the link before clicking it.

Frequently Asked Questions

The Bottom Line

URL structure is the grammar of your site’s addresses: the choice of words, separators, and folder depth that tells a reader and a crawler what a page is before it loads. Google’s rules are unglamorous but consistent — readable words, hyphens between them, a sensible hierarchy, and as few parameters as you can manage. Get it right once and, above all, keep it stable.