A slug is the short, human-readable label at the end of a web address that identifies one particular page. In example.com/blog/spring-menu, the slug is spring-menu. The name comes from newspaper publishing, where a "slug" was the short working title editors used to track a story.
Where slugs come from and how they are used
Most content systems create a slug automatically from the page title: they lowercase it, swap spaces for hyphens and strip punctuation, so "Our Spring Menu!" becomes our-spring-menu. You can usually edit it before publishing. When a request arrives, the site looks up which page owns that slug and renders it. That is why slugs must be unique within the same section: two posts cannot both be /blog/spring-menu.
The slug is one segment of the full URL. Together with the folder-like path before it, it forms the page's permalink.
A before-and-after example
An accountant publishes a post titled "5 Things Every Freelancer in Ontario Should Know Before Filing Their Taxes This Year". The auto-generated slug is 5-things-every-freelancer-in-ontario-should-know-before-filing-their-taxes-this-year. Trimmed by hand to freelancer-tax-filing-ontario, it is easier to read in a search result, easier to share, and it will not look wrong if the post is updated to "7 things" next year.
Writing a good slug
- Describe the page in a few words, using the term people search for.
- Lowercase letters, numbers and hyphens only. Google recommends hyphens over underscores to separate words.
- Drop filler words like "a", "the" and "and" when the meaning survives.
- Leave out years, counts and anything likely to change.
Slugs are a small part of on-page SEO. A clear slug helps people decide to click, but it will not make a weak page rank.
When to leave slugs alone
Getting the slug right matters most at the moment a page is first published. Once a page has links and search traffic, rewriting its slug for a tiny keyword tweak is rarely worth it. If you must change it, add a 301 redirect from the old address.
Common slug mistakes
- Keeping auto-generated slugs that are 15 words long or end in
-2because a draft already used the name. - Changing a live slug without a redirect, creating a 404 for everyone who had the old link.
- Using spaces, capitals or accented characters, which get percent-encoded into messy addresses.
- Repeating the folder name, as in
/services/plumbing-services.
Related terms
- URL: the full address a slug sits inside.
- Permalink: the stable address built from the slug.
- On-page SEO: where slug choices fit in.
- 301 redirect: what to add when a slug changes.