Hyphens or underscores?

Hyphens. Search engines treat them as word separators and underscores as joiners.

What happens to accented characters?

They are reduced to their base letters, so Café becomes cafe rather than a percent-encoded string.

How long should a slug be?

Three to six meaningful words. Filler words such as "the" and "how to" can usually go.

Can I change a slug after publishing?

You can, but it breaks existing links and loses accumulated ranking. Redirect the old URL permanently if you do.

No, slugs are generated in your browser as you type.

URL slug generator — Free, no signup

URL slug generator

Turn a title into a clean, URL-safe slug.

Title

Separator

Runs in your browser — nothing is sent anywhere.

This tool needs JavaScript, because the work happens on your own device rather than on a server. Everything below — the guide and the answers — works without it.

What a slug is for

A slug is the readable part of a URL — the compress-pdf-to-100kb in this site's own addresses. Good slugs help readers know where a link leads before they click, help search engines understand a page, and survive being pasted into messages without turning into a wall of percent signs.

What gets removed

Accents are stripped to their base letters, so Café Münchén becomes cafe-munchen rather than a percent-encoded mess. Punctuation is dropped, spaces and underscores collapse into your chosen separator, and repeated separators are reduced to one. Everything is lowercased, since URLs are case-sensitive on most servers and mixed-case slugs cause duplicate-content problems.

Hyphens, not underscores

Use hyphens. Google has said for years that it treats hyphens as word separators and underscores as joiners, which means compress_pdf may be read as one token where compress-pdf is read as two. Underscores are offered for systems that require them; for the public web, hyphens.

Length

Shorter is better. Slugs are truncated in search results and shared links, and the leading words carry the most weight. Three to six meaningful words is a good target — dropping filler like "the", "a" and "how to" usually improves a slug without losing meaning.

Do not change published slugs casually

Changing a slug changes the URL, which breaks every existing link and discards whatever ranking that page had accumulated. If you must, redirect the old address to the new one permanently. It is far easier to get it right the first time than to unpick it later.