What Is a URL Slug?

A full URL has several parts: a scheme (https://), a domain (example.com), an optional path made of segments separated by slashes, and sometimes a query string. The slug is the human-readable segment that names the individual page or post. In https://example.com/blog/what-is-a-url-slug, the path is /blog/what-is-a-url-slug and the slug is the final piece, "what-is-a-url-slug".

The word comes from print journalism, where a "slug" was a short label editors used to refer to a story while it moved through production. On the web it plays the same role: a stable, memorable handle for a page. Most content management systems create the slug automatically from the title, but you can almost always edit it before publishing.

Search engines read the words in a URL as a small signal about what the page is about, so a slug containing the right keywords reinforces the page's topic. Just as important, a clear slug appears in search results, browser tabs, and link previews, helping people decide whether to click.

Slugs also shape how shareable and trustworthy a link feels. A clean address like /best-running-shoes is easy to read aloud, type from memory, and paste into a message without looking broken. A cryptic one like /p?id=48213&cat=7 tells the reader nothing and can look like spam. Readable slugs make links friendlier wherever they travel.

Keep slugs lowercase to avoid confusion, since some servers treat /About and /about as different pages. Separate words with hyphens, not spaces or underscores: spaces get encoded into ugly %20 sequences, and search engines treat hyphens — but not underscores — as word boundaries, so "url-slug" reads as two words while "url_slug" can read as one.

Aim for short and focused. Include the one or two keywords that describe the page and drop filler. There is no need to repeat every word from the title or to stuff in stop words like "the", "a", "and", or "of"; trimming them usually makes the slug clearer, not weaker. Use only unreserved characters — letters, numbers, and hyphens — and let a slug generator handle accents, symbols, and punctuation for you.

The most damaging mistake is changing a slug on a page that is already live without setting up a redirect. The old URL is what other sites link to and what search engines have indexed; change it silently and those links break, returning 404 errors and erasing accumulated ranking. If you must change a slug, add a 301 redirect from the old address to the new one.

Other frequent errors include leaving spaces or special characters in the slug, which produce encoded gibberish like %20 and %26, and baking volatile details into it. Putting dates, numeric IDs, or category names in a slug — /2024/post-8842 — makes URLs brittle and meaningless, and forces awkward changes when content is updated or moved. Favor a stable, descriptive slug that will still make sense a year from now.