Slug Generator — URL-Friendly Slug from Any Text

A URL slug is permanent in a way the rest of a page is not

A title can be rewritten as often as you like at no cost. A URL cannot: changing it breaks every existing inbound link, bookmark and share unless you maintain a redirect — and redirects accumulate as technical debt, add a hop of latency, and are routinely lost in migrations and platform changes.

So the slug is one of the very few things on a page worth deciding once, deliberately, rather than iterating on. Everything below follows from that.

What the tool actually does to your text

Given Café: The Complete Guide it produces cafe-the-complete-guide. The steps, in order:

• Unicode normalisation, then removal of combining diacritical marks — so é becomes e and ñ becomes n, rather than being deleted outright.
• Special characters removed — commas, colons, parentheses, apostrophes, ampersands and question marks all go, leaving letters, digits, spaces, hyphens and underscores.
• Separators collapsed and trimmed — runs of spaces or separators become a single separator, and any leading or trailing separator is stripped.
• Lowercasing, on by default and toggleable.

One important limitation: because the transliteration works by stripping diacritics from Latin characters, non-Latin scripts are removed entirely rather than transliterated. A title written in Devanagari, Arabic, Cyrillic or Chinese will produce an empty or near-empty slug. If you publish in those scripts you will need either a proper transliteration library or a hand-written Latin slug — the tool will not warn you, it will simply return very little.

Use hyphens

Hyphens are the convention, and the mechanism is worth knowing rather than taking on faith: a hyphen is treated as a word separator, while an underscore is historically a word character. So top_seo_tools can be read as the single token "top_seo_tools", where top-seo-tools reads as three words.

The practical effect on ranking is small — this is not a penalty to avoid. But hyphens cost nothing, read better in a shared link, and are what every platform and reader expects. The tool offers underscores and dots for cases where a system requires them; absent such a requirement, use hyphens.

Keep it short and stable

Two rules do most of the work here, and both are about the slug still being right in two years:

• Avoid dates and counts. A slug containing a year makes the page look stale the moment the year turns, and top-7-tools locks you into seven — updating the article to nine either produces a lying URL or forces the redirect you were trying to avoid.
• Drop filler where meaning survives. how-to-write-a-good-slug loses nothing as write-a-good-slug. But do not mangle sense to save characters; an unreadable slug is worse than a slightly long one.

There is no length threshold that triggers a penalty, so ignore any specific number quoted as a limit. The practical constraint is that long URLs get truncated in share previews and search results, so a slug whose meaning survives being cut off is more useful than one where it does not.

Finally, the slug does not have to match the title, and forcing an entire headline into it is the most common cause of unwieldy URLs. And remember the slug must be unique within its scope — most systems resolve a clash by appending a number, which produces exactly the unreadable URL you were avoiding, so it is better to choose a distinct one yourself. For other developer utilities, see the UUID generator.