Why Are URL Slugs Called Slugs?

Why "Slug"?

The term "slug" in the context of URLs actually comes from the world of publishing.

In traditional print journalism, a slug was a short label used to identify a story in progress. Editors and journalists used it as a quick, shorthand title—often a few keywords—to refer to a piece of content before it had a final headline.

When the web came along, developers borrowed the term to describe the human-readable part of a URL that identifies a page in a simple and concise way, and often derived from the content's title (e.g., "why-is-url-slug-called-slug" in a URL). The name stuck because, like a news slug, it’s a brief, meaningful label that helps organize and identify content, making URLs more user-friendly and SEO-optimized.

Fun Fact:

Some say it may also relate to the word "slug" (as in a slow-moving creature), since slugs were originally short, lazy identifiers compared to full headlines.

How to optimize URL slugs for SEO

Optimizing URL slugs for SEO is a critical part of on-page optimization, as slugs help search engines and users understand the content of a page. Here are the best practices for creating SEO-friendly URL slugs:

1. Keep Slugs Short and Descriptive

• Why: Short, clear slugs are easier for users to read and for search engines to interpret.

• How: Use 3–5 words that summarize the page’s content (e.g., /best-seo-practices instead of /best-search-engine-optimization-practices-for-2025).

• Tip: Aim for slugs under 60 characters to ensure they’re concise and fully displayed in search results.

  
  

2. Include Relevant Keywords

• Why: Keywords in slugs signal to search engines what the page is about, boosting relevance for targeted queries.

• How: Incorporate the primary keyword naturally (e.g., /seo-friendly-urls for a page about URL optimization).

• Tip: Avoid keyword stuffing; use only one primary keyword or phrase to maintain clarity.

  
  

3. Use Hyphens to Separate Words

• Why: Hyphens (-) are the standard separator for search engines, improving readability and crawlability.

• How: Replace spaces or underscores with hyphens (e.g., /url-slug-best-practices instead of /url_slug_best_practices or /url slug best practices).

• Tip: Avoid special characters (e.g., &, %, ?) as they can confuse crawlers or break URLs.

  
  

4. Make Slugs Human-Readable

• Why: User-friendly slugs improve click-through rates and shareability.

• How: Write slugs that reflect the page’s content in plain language (e.g., /how-to-optimize-slugs instead of /post-id-12345).

• Tip: Remove unnecessary words like “a,” “the,” or “and” (e.g., /optimize-url-slugs instead of /how-to-optimize-a-url-slug).

  
  

5. Use Lowercase Letters

• Why: Consistent lowercase URLs prevent duplicate content issues, as some servers treat Slug and slug as different pages.

• How: Always use lowercase (e.g., /seo-tips instead of /SEO-Tips).

• Tip: Set up 301 redirects for any mixed-case URLs to the lowercase version.

  
  

6. Avoid Stop Words and Filler Words

• Why: Stop words (e.g., “is,” “for,” “in”) add length without SEO value.

• How: Omit unnecessary words to keep slugs concise (e.g., /best-seo-tools instead of /best-tools-for-seo).

• Tip: If stop words are essential for clarity, include them sparingly.

  
  

7. Ensure Uniqueness and Avoid Duplication

• Why: Unique slugs prevent indexing issues and clearly differentiate pages.

• How: Create distinct slugs for each page, even if topics are similar (e.g., /on-page-seo and /off-page-seo).

• Tip: Audit your site with tools like Screaming Frog to identify and fix duplicate or similar slugs.

  
  

8. Align Slugs with Content Updates

• Why: Slugs should reflect current content to maintain relevance and avoid confusion.

• How: Update slugs when revising content (e.g., change /2024-seo-trends to /2025-seo-trends if the page is updated).

• Tip: Set up 301 redirects from old slugs to new ones to preserve link equity and avoid 404 errors.

  
  

9. Avoid Dynamic Parameters in Slugs

• Why: Dynamic URLs with parameters (e.g., /page?id=123) are less user-friendly and harder for search engines to index.

• How: Use static, descriptive slugs instead (e.g., /product/blue-running-shoes instead of /product?id=456).

• Tip: Rewrite dynamic URLs using .htaccess or CMS settings in platforms like WordPress.

  
  

10. Test and Monitor Slug Performance

• Why: Tracking slug performance helps identify opportunities for improvement.

• How: Use Google Search Console to monitor click-through rates, impressions, and rankings for pages with specific slugs.

• Tip: A/B test slugs by creating variations (with redirects) to see which performs better in search results.

  
  

Additional Notes:

• CMS Support: Platforms like WordPress, Shopify, or Squarespace allow easy slug customization in permalink settings. Ensure slugs are auto-generated based on titles but manually refine them for SEO.

• Cultural Sensitivity: If targeting global audiences, ensure slugs avoid words or phrases that could be misinterpreted in other languages.

• Consistency: Maintain a consistent slug structure across your site (e.g., always use /category/subcategory/page or /page formats) for better site architecture.

  
  

By following these practices, your URL slugs will be more search-engine-friendly, improve user experience, and contribute to higher rankings and click-through rates.