SEO

URL Slug

A URL slug is the path segment at the end of a URL, after the domain or subfolder, that identifies a specific page. In example.com/blog/url-slug, the url-slug portion is the slug, and it is best kept short, keyword-rich, and hyphen-separated.

A URL slug is the path segment at the end of a URL, sitting after the domain and any subfolders, that identifies a specific page (e.g., example.com/blog/url-slug).
The core principles are keeping it short, including the main keyword, separating words with hyphens (-), using lowercase, and avoiding dates and ID numbers.
A slug is one part of the broader URL structure design. It is a very lightweight ranking factor, but it affects readability and click-through for users.

Overview

A URL slug is the path segment at the end of a URL, after the domain or a subfolder, that identifies a specific page. In the address example.com/blog/url-slug, for example, url-slug is the slug. Ahrefs defines a slug as "the part of a URL that comes after the domain name or subfolder, following a slash (/)."

A slug acts as a human-readable label that lets people guess what the page is about. The basic approach, then, is to keep it short while still carrying a keyword that signals the page's topic, separating words with hyphens. That said, a slug is only one piece of the overall URL structure design, which also covers the protocol, domain, subfolders, and parameters. A slug alone does not represent the entire URL.

Best Practices

Short, but meaningful — Carry the core topic or keyword without padding the slug with unnecessary length.
Hyphens to separate words — Use hyphens (-) rather than underscores (_) to break up words. Hyphens help both users and search engines recognize distinct concepts more easily.
Use lowercase — Some servers treat case as significant, so standardizing on lowercase reduces typos and duplicate URLs.
Avoid dates and ID numbers — Embedding a year or a long ID number forces redirects when you update the content and makes the URL harder to reuse.
Use readable words — Prefer human-readable words over long ID parameters, and write them in the target audience's language where possible (percent-encode non-ASCII characters).

Good Examples

example.com/seo/url-slug
example.com/blog/keyword-density
example.com/best-domain-providers

Bad Examples

example.com/index.php?topic=42&area=3a5ebc944f41daa6f849f730f1 (unreadable IDs and parameters)
example.com/what_is_keyword_density_and_why (underscores and excessive length)
example.com/Best-Domain-Providers-2022 (uppercase and an embedded year)

Rationale

Google Search Central's documentation on URL structure best practices recommends using "readable words rather than long ID numbers" and separating words with "hyphens (-) rather than underscores (_)." It also advises converting "all text to the same case" when a server treats cases as the same, and keeping URLs simple by removing unnecessary parameters that do not change the content.

Ahrefs describes the slug as a "very lightweight factor," yet notes that a descriptive slug improves the user experience and increases the likelihood of a click when shared. It also recommends leaving dates out to reduce redirect overhead during updates (/best-domain-providers vs. /best-domain-providers-2022). Semrush likewise presents using hyphens, including a keyword, keeping the slug short, using lowercase, and avoiding numbers and dates as its core principles.