A URL slug is the part of a web address that identifies a specific page. In the URL example.com/blog/how-to-write-better-headlines, the slug is how-to-write-better-headlines. It is the human-readable identifier that appears at the end of the URL and tells both users and search engines what the page is about before they click.

Slugs seem like a minor detail but they affect SEO in ways that compound over time. A page with a descriptive slug that matches what people search for is more likely to rank for those terms than the same page with a generic or auto-generated slug like page-1247 or a slug that uses URL-encoded characters for spaces and special characters.

What makes a good slug

A good slug is short, descriptive, and uses only lowercase letters, numbers, and hyphens. It contains the main keyword for the page. It does not include stop words like the, a, an, and, or, in, of when they can be removed without changing the meaning. And it uses hyphens rather than underscores between words.

Google has stated that it treats hyphens as word separators in URLs, meaning how-to-write is read as three separate words. Underscores are treated differently; how_to_write is read as one word. For keyword recognition in URLs, hyphens are the correct choice.

Shorter slugs are generally better when length can be reduced without losing meaning. A slug of how-to-compress-images is clearer and more useful than how-to-compress-images-for-your-website-without-losing-quality-using-free-tools, even though the longer version contains more keywords. Overly long slugs look unwieldy when shared, get truncated in some interfaces, and do not significantly improve ranking beyond including the primary keyword.

Handling special characters and non-English text

Spaces in URLs are encoded as either %20 or plus signs, both of which look bad in a slug. Converting spaces to hyphens is the standard approach. Accented characters, characters from non-Latin scripts, and other special characters should be either transliterated to their ASCII equivalents or removed.

A slug generator handles these conversions automatically. Paste a page title and the tool produces a properly formatted slug: lowercase, spaces converted to hyphens, special characters removed or replaced, stop words optionally removed. Manual formatting is error-prone and tedious for large numbers of pages, which is where a generator saves meaningful time.

Slugs and URL structure

The full URL path includes the slug along with any parent categories or folders. A blog post slug might be how-to-write-better-headlines while the full URL is example.com/blog/how-to-write-better-headlines. The slug is just the last segment.

Some CMS platforms and frameworks generate slugs automatically from page titles. These auto-generated slugs often include stop words and sometimes use encoding for characters rather than removing them. Reviewing and editing auto-generated slugs before publishing is worthwhile for important pages where the URL will be shared and indexed.

Changing existing slugs and redirects

Changing a published page slug is a decision that requires care. The original URL may have inbound links from other sites, may appear in search engine indexes, and may be bookmarked by users. Changing the slug without setting up a redirect from the old URL to the new one breaks all of these links and loses any link authority the old URL had accumulated.

A 301 redirect from the old URL to the new one preserves most of the link value and ensures anyone who follows an old link reaches the current page. Setting up this redirect is essential when changing a slug on a page that has been live long enough to have accumulated links or search traffic.

For new pages that have not yet been indexed or linked to, getting the slug right before publishing is much simpler than correcting it after. Taking a few seconds to review and optimize the slug before a page goes live avoids the redirect management step entirely.

Slugs for different content types

Blog posts typically use title-based slugs with stop words removed. A post titled How to Write Better Email Subject Lines becomes how-to-write-better-email-subject-lines or write-better-email-subject-lines with the most common stop words removed.

Product pages in e-commerce often use product names as slugs. A product called Blue Wireless Headphones Model X becomes blue-wireless-headphones-model-x. Including the model identifier is useful because it disambiguates between similar products and matches searches that include the model number.

Category pages use category names. A category called Photography Equipment becomes photography-equipment. Keeping category slugs short and generic rather than trying to include keywords lets individual product or article slugs within the category carry the more specific keyword terms.

Slugs and SEO

The URL slug is one of the on-page SEO elements that search engines use to understand what a page is about. Including the primary keyword for a page in its slug tells search engines directly about the page's topic before they even read its content. A URL like /how-to-compress-images is more informative to a search engine than /post-12847, and this relevance signal contributes to ranking for related queries.

Short slugs perform better than long ones for several reasons. They are easier to read and share, they fit more cleanly in social media posts and messaging, and they are less likely to be truncated in search result displays. When a page title is long, creating a shorter slug that contains the most important keywords rather than converting the entire title to a slug produces cleaner URLs.

Changing slugs on existing pages breaks all external links to those pages unless permanent redirects are set up. The SEO value accumulated in links pointing to the old URL transfers to the new one through a 301 redirect, but the redirect adds a small overhead and may not transfer all link equity indefinitely. Choosing a good slug when a page is first created and not changing it afterward is preferable to optimizing slugs for existing pages that already have external links.

Slug conventions across different platforms

WordPress generates slugs automatically from post titles but allows editing before publishing. The automatic generation converts spaces to hyphens, removes special characters, and lowercases everything. Editing the generated slug to remove stop words like the, a, and, of before publishing produces cleaner and shorter URLs. Once a WordPress post is published and indexed, changing the slug requires setting up a redirect from the old URL.

Static site generators like Jekyll, Hugo and Gatsby derive slugs from filenames or front matter fields. The convention in these systems is to name content files using the intended slug format, which means the filename and the URL path stay in sync. Content management systems vary in how they handle slug generation and editing, but most allow customization before publication.

International and non-Latin characters in slugs require special handling. Some systems transliterate characters from other scripts to their Latin equivalents, turning a French accent like é into e. Others percent-encode the characters, producing URLs that look like strings of percent signs and hexadecimal digits when not rendered by a browser. For multilingual content, choosing a consistent policy for non-Latin characters in slugs before building a large content library prevents inconsistency that is difficult to fix retroactively.

Testing slugs before finalizing them involves checking that the generated URL renders correctly in browsers and is readable when shared in messaging applications. Some URL shorteners and messaging platforms display URLs in truncated form, and a slug that is meaningful when truncated to 30 characters communicates more than one that becomes unrecognizable at that length. Short, keyword-rich slugs perform better across all these display contexts.

Redirects from old slugs to new ones pass link equity but create a small amount of technical overhead. Tools that audit your site for redirect chains, where one redirect points to another redirect before reaching the final destination, help keep the URL structure clean. Long redirect chains slow page loading and dilute the link equity being passed, so resolving chains to point directly to the final destination is good maintenance practice.