URL Slugs: Hyphens, Underscores, and Boring Consistency

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For human-readable URL slugs, prefer lowercase words separated by hyphens:

1
/products/green-dress

rather than:

1
2
/products/green_dress
/products/greendress

Search engines generally interpret hyphens as word separators, and hyphenated slugs are easier for people to scan. This is a convention, not a magical ranking button.

Practical rules

  • Use lowercase letters.
  • Separate words with hyphens.
  • Keep slugs short but descriptive.
  • Avoid unstable details such as temporary status or presentation labels.
  • Preserve old URLs with redirects when a slug changes.
  • Do not put secrets or sensitive data in a URL; URLs leak into history, logs, analytics, and referrer headers.

A clean slug improves readability, but content quality, links, page performance, and stable redirects matter far more than winning a philosophical war between - and _.

References