URL Slug

A URL slug is a human-readable part of a web address that helps identify a specific page, post, product, category, or other resource. It commonly appears as the final segment of the URL path. A URL slug commonly uses words separated by hyphens to describe the page in a concise, readable form.

For example, in the URL:

https://example.com/seo/url-slug

the phrase url-slug is the slug.

What Is a URL?

A URL, or Uniform Resource Locator, is the complete address used to identify and access a resource on the internet. A URL can point to a webpage, image, document, video, or another online resource. MDN defines a URL as the address of a unique resource on the internet.

A typical webpage URL may contain several parts:

https://example.com/seo/url-slug

• Protocol: https:// tells the browser how to communicate with the website.
• Domain: example.com identifies the website.
• Path or directory: /seo/ helps organize the resource within the site.
• Slug: url-slug identifies the individual page within that path.

Additional Elements in a URL

A URL can contain additional elements that provide tracking information, point to a specific section, control displayed content, or carry a search query. These elements are generally separate from the page’s URL slug.

• Tracking parameters help analytics tools identify where a visitor came from.
  Example: https://example.com/seo/url-slug?utm_source=newsletter&utm_medium=email
• Page fragments point to a specific section of a webpage.
  Example: https://example.com/seo/url-slug#best-practices
• Filtering or sorting parameters can control which items are displayed or how they are arranged.
  Example: https://example.com/products?category=shoes&sort=price
• Search parameters carry the search query submitted by a user.
  Example: https://example.com/search?q=technical+seo

What Is a URL Slug?

A slug is a human-readable identifier used within a URL path to help identify a particular resource. For example:

https://example.com/blog/technical-seo

In this URL, technical-seo is the slug.

Content management systems such as WordPress commonly create slugs from page or post titles. WordPress describes the post name used in a permalink as a sanitized version of the title, and site owners can customize permalink structures through WordPress settings.

URL slugs may be used for webpages, blog posts, product pages, author archives, category pages, glossary entries, and other forms of online content.

URL Slug vs. URL vs. Permalink

A slug, URL, and permalink are related but not identical terms. The URL is the complete address, while the slug is usually one human-readable segment of its path. A permalink is the stable URL intended to serve as the long-term address of a specific page, post, or other piece of content.

Not every URL is a permalink. Preview URLs, search URLs, tracking URLs, and other temporary or dynamically generated addresses may also point to content without serving as its main permanent address. In WordPress, the slug often forms part of that permalink.

For example, consider this page:

https://example.com/blog/keyword-research

URL: https://example.com/blog/keyword-research

Slug: keyword-research

Permalink: the permanent URL assigned to that post, which in this case is the full address above.

WordPress describes permalinks as the permanent URLs used for individual posts and other content, with the post-name component derived from the post slug.

How a URL Slug Works

When a page is created, the website assigns it a unique URL. The website’s server or content management system uses the URL path, including the slug, to identify which resource should be returned when the address is requested.

For example, a page titled “What Is Technical SEO?” may receive the following slug:

what-is-technical-seo

The complete URL might be:

https://example.com/seo/what-is-technical-seo

When someone opens the URL, the website uses that address to locate the corresponding resource and return it to the browser.

Search engines encounter and process URLs when discovering, crawling, indexing, and displaying webpages. A clear slug may provide additional context about the page’s subject. However, the slug is only one small element of search optimization and does not determine rankings by itself.

Example of a URL Slug

Consider an article titled:

How to Conduct Keyword Research for SEO

A suitable URL may be:

https://example.com/seo/keyword-research

In this example, keyword-research is the slug. It communicates the main topic without repeating every word from the full title. A less concise version might be:

https://example.com/seo/how-to-conduct-keyword-research-for-seo-complete-guide-2026

This slug is unnecessarily long and may become outdated if the year changes.

A less descriptive URL might use an identifier instead of readable words:

https://example.com/post?id=78492

Although this URL can function correctly, the identifier provides little information about the page’s subject.

How to Optimize a URL Slug for SEO

A good URL slug should primarily help users understand what a page is about. Google recommends using simple, descriptive URLs with readable words and separating words with hyphens rather than underscores.

For SEO-friendly URL slugs:

• Describe the page clearly. Use words that accurately represent the main subject.
• Use the primary keyword naturally. Include a keyword when it accurately describes the page, but do not repeat keywords unnecessarily.
• Keep the slug concise. Remove unnecessary words while preserving meaning.
• Separate words with hyphens. Google recommends using hyphens rather than underscores to separate words in URLs.
• Use readable words. Avoid long strings of numbers, codes, or unnecessary parameters when a descriptive structure is available.
• Avoid unnecessary dates. A year in the slug can make an evergreen page appear outdated unless the date is important to the content.
• Choose the slug before publishing. Changing an established URL later may require redirects and updates to internal links.
• Avoid keyword repetition. A slug such as seo-keyword-seo-keyword-research adds no useful context and looks unnatural.

URL Slug Mistakes to Avoid

A URL slug should be clear, readable, and closely related to the page topic. Problems often arise when slugs are unnecessarily complex, inconsistent, or changed after publication.

Common mistakes include:

• Changing an established slug without a valid reason. URL changes can break existing links and may require redirects.
• Failing to redirect the old URL. If a published slug changes, a permanent 301 redirect should normally send the old URL to the new destination. Google recommends permanent redirects when URLs move.
• Removing too many words. Shorter is not always better if the resulting slug becomes vague or difficult to understand.
• Using inconsistent capitalization or naming patterns. Consistency helps keep URL structures predictable and easier to manage.
• Creating multiple URLs for the same content without proper canonicalization or redirects. This can create unnecessary duplicate URL versions.

Changing a URL slug after publication can break internal links, backlinks, and bookmarks. It may also produce a 404 error if the old address is not redirected. Repeated changes can also make crawling and indexing more complicated.

A well-formed URL slug should be descriptive, stable, and easy to understand. Reviewing it before publication helps avoid unnecessary URL changes later.