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What is a URL slug (and how to make a good one)?

5 min read

A slug is the human-readable part of a URL that names a page. Here's what makes a slug good for readers and for SEO.

A URL slug is the human-readable part of a web address that identifies a specific page. It is the piece at the end of the URL, after the domain and any folders. In example.com/blog/what-is-a-url-slug, the slug is what-is-a-url-slug. A good slug tells a person (and a search engine) what the page is about before they even click, and you can shape it with a slug generator in seconds.

Where the slug sits in a URL

Breaking a full address into its parts makes it clear:

https://example.com/blog/what-is-a-url-slug
└─┬──┘   └────┬────┘ └─┬─┘ └───────┬───────┘
scheme     domain    path        slug

The scheme and domain point at the site, the path groups pages into sections, and the slug names the individual page. It is the one part of the address that describes the content itself, which is exactly why it is worth getting right.

What makes a good slug

  • Lowercase only. URLs can be case-sensitive, so mixed case invites duplicate-page confusion. Keep everything lowercase.
  • Hyphens between words. Use -, not underscores or spaces. Search engines read hyphens as word breaks; spaces become ugly %20 codes.
  • Short and focused. A few meaningful words beat a long sentence. Trim filler so the main idea stands out.
  • Include the main keyword. Put the term the page is actually about in the slug, near the front where possible.
  • Drop stop words and noise. Words like “the”, “a” and “of”, along with dates and database IDs, usually add length without meaning.
  • Keep it stable. Once a page is published, changing its slug breaks existing links unless you add a redirect. Decide early and leave it alone.

Why slugs matter, for SEO and for people

For readers, a clean slug is honest signage: it shows what a link leads to, so it is easier to trust, remember, and share. A tidy slug also looks better when pasted into a chat or a document, with no stray symbols or gibberish.

For search engines, the slug is a small but real relevance signal. It reinforces the topic of the page and often appears in the search result itself, so a descriptive slug can nudge click-through up. It is not a magic ranking lever, but it is easy points that cost nothing.

Slugs in WordPress and other CMSs

Most content management systems generate a slug automatically from your title. Publish a post called “What Is a URL Slug?” and the system will typically create what-is-a-url-slug for you, lowercasing the text and replacing spaces with hyphens. The key thing to know: that value is editable. Before you hit publish, trim it to the essentials, because changing it later means setting up a redirect so old links keep working.

Good vs. bad slugs

Good                          Bad
/pricing                      /Page_2?id=48273
/blog/what-is-a-url-slug      /blog/2026/03/11/the-post-about-slugs
/docs/api/authentication      /docs/API%20Authentication
/contact                      /contact-us-now-click-here!!

The good column is lowercase, hyphen-separated, keyword-first, and free of dates, IDs, and encoded characters. The bad column shows the usual culprits: capital letters, spaces, query-string IDs, redundant dates, and punctuation that has no business in a URL.

Want a clean slug without hand-editing every character? Paste any title into our free URL slug generator, and it will lowercase the text, swap spaces for hyphens, and strip out the characters that do not belong, all in your browser.

Frequently asked questions

What is a URL slug?
A slug is the human-readable part of a URL that identifies a specific page. It is the segment at the end of the address, after the domain and any folders. In example.com/blog/what-is-a-url-slug, the slug is 'what-is-a-url-slug'.
What is a slug in SEO?
In SEO, the slug is the part of the URL you can customise to describe the page in plain words. A clear, keyword-rich slug helps both search engines and people understand what the page is about before they open it, which can improve relevance and click-through.
What is a slug in WordPress?
In WordPress and most content management systems, the slug is auto-generated from the page or post title (lowercased, with spaces turned into hyphens). You can edit it in the editor, and it is best to finalise it before publishing so the URL stays stable.
Should slugs use hyphens or underscores?
Use hyphens. Search engines treat hyphens as word separators, so 'url-slug' reads as two words, while 'url_slug' can be read as one. Hyphens are the long-standing recommendation for readable, SEO-friendly URLs.

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