URL Structure
URL structure is the practice of designing every URL on a site to be concise, meaningful, and consistently hierarchical so that both people and search engines can understand it easily. The core is to use lowercase letters, hyphens between words, readable terms, and a logical folder hierarchy.
- URL structure is how a site's entire set of URLs is designed for people and search engines to understand, covering the whole blueprint rather than a single path segment like a url slug.
- Google recommends readable words instead of ID numbers, and hyphens (-) rather than underscores (_) to separate words.
- The guiding principles are consistent lowercase, short and meaningful words, a logical folder hierarchy, and removal of unnecessary parameters.
- An abundance of meaningless parameters multiplies URLs that point to the same content, hurting crawl efficiency and indexing.
- HTTPS has been a lightweight ranking signal since 2014, and volatile elements such as dates and session IDs are best left out of URLs.
Overview
URL structure is the practice of designing the address of every page on a website to be concise, meaningful, and consistently hierarchical, so that people and search engines can grasp it at a glance. A good URL structure lets you guess what a page is about and where it sits within the site from the address alone.
A url slug is a single path segment of a URL, that is, one of its component parts. URL structure differs in scope: it is the overall blueprint that decides which words those slugs use, what folder hierarchy they form, and which conventions (lowercase, hyphens, and so on) govern how they are combined.
Best Practices
| Aspect | Recommendation | Reason |
|---|---|---|
| Word separation | Use hyphens (-); avoid underscores (_) | Google reads hyphens as word separators, making concepts easy to identify |
| Letter case | Stick to lowercase | Mixed case can create duplicate content problems |
| Word choice | Readable, meaningful words in the audience's language | An address people can understand instead of a long ID number |
| Hierarchy | Logical folder structure; avoid excessive depth | Makes content relationships easy for people and search engines to follow |
| Parameters | Remove unnecessary parameters that do not change content | Prevents crawl and indexing waste from a flood of duplicate URLs |
| Dates and numbers | Exclude where possible | Addresses can become mismatched or look stale when content is updated |
| Protocol | HTTPS | A lightweight ranking signal since 2014 |
Good URLs and Bad URLs
Good examples
https://example.com/shoes/running/nike-pegasus
https://example.com/blog/url-structure-guide
Bad examples
https://example.com/index.php?topic=42&area=3a5ebc944f41daa6
https://example.com/Category/New_Products/Item_00123?sid=abcWhen non-ASCII characters are involved, Google recommends UTF-8 based percent-encoding and advises using words in the audience's language (transliterating when necessary). When parameters are used, Google recommends the standard notation: joining key and value with an equals sign (=), additional parameters with an ampersand (&), and multiple values with commas (,).
Rationale
Google Search Central's URL structure best-practices document explicitly states to "use hyphens (-) instead of underscores (_) to separate words" and recommends readable words over long ID numbers. As an example, it suggests a form like /wiki/Aviation rather than /index.php?topic=42&area=3a5e.... It also warns that overly complex URLs can create an unnecessary number of URLs pointing to identical or similar content, causing Googlebot to waste bandwidth or fail to finish indexing.
Ahrefs' guide to SEO-friendly URLs recommends always using lowercase, replacing spaces with hyphens, and building short, readable slugs based on the primary keyword. It further advises using subfolders to express hierarchy while avoiding excessive depth, steering clear of dates, URL parameters, and subdomain overuse, and serving content over HTTPS (a ranking signal since 2014).
Implementation Checklist
- Standardize all URLs to lowercase and separate words with hyphens (-).
- Strip long IDs, session IDs, and unnecessary tracking parameters from addresses.
- Use readable, meaningful words in the audience's language.
- Organize the folder hierarchy to match the content structure and avoid excessive depth.
- Leave dates out of evergreen content URLs so the addresses stay valid over time.
- Serve the entire site over HTTPS, and consolidate duplicate URLs for the same content with canonical tags and redirects.
- Handle non-ASCII characters with UTF-8 percent-encoding.