Last updated 3 September 2026
What this does
A slug is the readable part of a URL that identifies a page — the how-to-bake-bread in example.com/how-to-bake-bread. This tool lowercases your text, replaces spaces and punctuation with your chosen separator, strips accents down to their plain letters, and removes anything that isn't safe in a URL — so you get a clean slug ready to paste into a CMS, a router, or a file name.
What makes a good slug
A slug is the human-readable part of a URL, and it does two jobs at once: it tells a person what the page is before they click, and it gives a search engine a plain-text signal about the content. Both jobs favour the same qualities — short, lowercase, hyphen-separated, and made of the words that actually describe the page.
Three or four meaningful words is usually the sweet spot. /how-to-resize-an-image reads well and fits in a search result; /how-to-resize-an-image-in-your-browser-for-free-2026 gets truncated with an ellipsis and adds nothing. Dropping filler words like a, the and to is fine and usually makes the slug clearer, not weaker.
Accents, other scripts and the safe character set
Browsers can display non-ASCII characters in a URL, but what actually travels over the network is a percent-encoded version. A slug written as café-münchen becomes caf%C3%A9-m%C3%BCnchen the moment someone copies it into a message or a spreadsheet, which is unreadable and easy to break. Transliterating to cafe-munchen keeps the link intact everywhere it is pasted.
One rule worth treating as absolute: once a slug is published and linked to, changing it breaks every existing link and loses whatever ranking that address has accumulated. If a slug genuinely has to change, set up a permanent redirect from the old address to the new one rather than simply retiring it.
Common questions
What is a slug?
The slug is the part of a URL that identifies a page in a human-readable way, like the '/how-to-bake-bread' in example.com/how-to-bake-bread. It's lowercase, uses hyphens or underscores instead of spaces, and skips punctuation and special characters.
Hyphens or underscores — which should I use?
Hyphens are the standard choice for URLs — Google explicitly treats a hyphen as a word separator but treats an underscore as joining words together, so 'my-post' is read as two words while 'my_post' can be read as one. Use underscores only if a specific platform or convention requires them.
Does it handle accented letters and other languages?
Common accented Latin letters (like é, ñ, ü) are converted to their plain equivalent (e, n, u) rather than dropped, so a title stays readable in the slug. Characters from non-Latin scripts (like Arabic, Chinese, or Cyrillic) are removed, since slugs are conventionally ASCII-only.
Is this saved or uploaded anywhere?
No — the conversion happens entirely in your browser as you type. Nothing is sent to a server or stored anywhere.
Should a slug use hyphens or underscores?
Hyphens. Search engines treat a hyphen as a word separator and an underscore as a joiner, so image_resizer can be read as a single token while image-resizer is read as two words. Underlined links also visually hide underscores.
How long should a slug be?
Three to five meaningful words is a good target. Long slugs get truncated in search results and messaging apps, and the extra words rarely add signal. Removing articles and prepositions usually improves clarity rather than harming it.
Can I change a slug after publishing?
You can, but every existing link to the old address will break and any ranking it held is lost unless you redirect. If the change is necessary, add a permanent 301 redirect from the old slug to the new one and leave it in place indefinitely.