What Is a URL Slug and Why Does It Matter for SEO?

In the address example.com/blog/how-to-count-words, the part after the last slash, how-to-count-words, is the slug. It identifies a single page and is one of the simplest on-page SEO elements to get right.

Why slugs matter

Search engines use the words in a URL as one of several signals about what a page covers. A clear slug also tells a reader what to expect before they click, and it looks more trustworthy when shared in a message or social post.

Rules for a good slug

• Use lowercase letters. Servers can treat upper and lower case as different addresses.
• Use hyphens, not underscores. Google treats hyphens as word separators.
• Drop filler words such as the, a, and, of when the meaning stays clear.
• Avoid special characters like accents, apostrophes and question marks.
• Keep it short, usually three to five words.
• Include the main keyword of the page.

Good and bad examples

Poor: /blog/How_To_Count_The_Words_In_Your_Essay_Online_For_Free_2026
Better: /blog/how-to-count-words-online

Avoid dates in slugs

A year in the slug makes the page look outdated as soon as the year changes, even if you update the content. A timeless slug can stay the same for years.

Changing a slug later

Changing the slug of a live page breaks the old address. If you must do it, set up a 301 redirect from the old URL to the new one so visitors and search engines land in the right place.