🔍Regex Recipes

URL Slug Validation

Validate URL-friendly slugs with lowercase letters, numbers, and hyphens.

Pattern

^[a-z0-9]+(?:-[a-z0-9]+)*$

Explanation

Matches lowercase alphanumeric strings with hyphens as separators. No leading, trailing, or consecutive hyphens.

Examples

Valid slug

Input

hello-world

Output

✓ Match

Valid with numbers

Input

post-123-update

Output

✓ Match

Invalid - uppercase

Input

Hello-World

Output

✗ No match

Invalid - trailing hyphen

Input

hello-world-

Output

✗ No match

Invalid - spaces

Input

hello world

Output

✗ No match

Code Examples

JavaScript - Generate Slug

function createSlug(text) {
  return text
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-|-$/g, '');
}

const slug = createSlug('Hello World!'); // 'hello-world'

Try it Now

Open in Regex Tester

💡 Tips

Always normalize to lowercase before validation
Remove diacritics for international characters
Consider maximum length limits (typically 50-100 chars)
Preserve SEO-friendly keywords in slugs