What Is a Slug and How to Create SEO-Friendly URLs

The slug is that readable part of a URL that describes the page: in miguelacm.es/blog/what-is-a-slug, the slug is what-is-a-slug. It seems minor, but it affects SEO, usability and how your content is shared. This guide explains how to do them right.

What is a slug

A slug is the simplified, readable version of a page's title, used in its URL. It turns "What Is a Slug? 2026 Guide" into what-is-a-slug-2026-guide. It's what comes after the domain and folders, identifying the specific content.

Why it matters for SEO

Keywords in the URL help Google and the user understand what the page is about before clicking.
Clean, readable URLs get more clicks: /blog/bread-recipes is more inviting than /blog/?p=4827.
They share better: a descriptive URL gives context when someone pastes it in social media or messages.

The rules of a good slug

Lowercase only. URLs are case-sensitive on some servers; lowercase avoids duplicates and confusion.
Hyphens, not spaces or underscores. Google recommends - to separate words. Spaces become ugly %20.
No accents or special characters. acción → accion. Avoid ñ, accents, &, ?, etc.
Short and descriptive. Include the main keyword and drop the filler. Better homemade-bread-recipes than the-best-homemade-bread-recipes-you-can-make-today.
No unnecessary stop words. Words like "the", "of", "and", "for" are usually extra: how-to-make-bread beats how-you-can-make-the-bread.
Unique and stable. Don't change it once published (it'd break links); if you must, use a 301 redirect.

From title to slug, step by step

Title: "How to Optimize Images for the Web in 2026"

To lowercase: how to optimize images for the web in 2026
Remove stop words: optimize images web 2026
Spaces to hyphens: optimize-images-web-2026

Result: a clean slug, with keyword and easy to read.

You can generate slugs like this instantly with the slug generator on this site, which transliterates accents, removes symbols and applies hyphens automatically.

Common mistakes

Slugs with unnecessary date or ID: /12345-my-article adds nothing for the user.
Changing the slug without a redirect: you break external links and lose ranking.
Mile-long slugs: repeating the whole title with stop words dilutes the keywords.
Non-ASCII characters: accents and ñ may work, but cause compatibility and sharing issues.

Frequently asked questions

Does the slug affect ranking? It's a minor but real factor: it helps with relevance and improves CTR. Not the most important thing, but it adds up.

Can I change an already-published slug? Yes, but set a 301 redirect from the old to the new so you don't lose links or ranking.

Hyphen or underscore? Hyphen (-). Google treats the hyphen as a word separator and the underscore not.

Is my data uploaded? No, if you use a local generator. Everything happens in your browser.

Turn any title into a friendly URL with the free slug generator, 100% in your browser.