A 404 error (or "404 Not Found") is an HTTP status code returned by a web server when a requested page does not exist at the specified URL. In SEO, 404 errors waste crawl budget, break link equity chains, and create broken links, and create a poor user experience. While some 404s are natural and harmless, large numbers of 404 errors on important pages signal site quality issues to search engines.

Types of 404 Errors

  • Standard 404: The server correctly returns a 404 status code for a page that does not exist
  • Soft 404: A page that appears to return content (200 status) but actually shows an error message. Google detects these and treats them as errors
  • Custom 404 page: A branded error page that helps users navigate back to useful content, reducing bounce rate
  • 410 Gone: Similar to 404 but explicitly tells search engines the page was intentionally removed and will not return
Key point: Not all 404s are bad. If a page genuinely does not exist and never had backlinks or traffic, a 404 is the correct response. The problem arises when important pages with backlinks and rankings return 404 errors.
404 Error SEO impact metrics chart showing bounce rate, page views, user engagement, and recovery strategy - seoisalive.com

How to Find and Fix 404 Errors

  • Google Search Console: Check the Pages report for "Not found (404)" errors
  • Crawl tools: Use Screaming Frog or Ahrefs Site Audit to find broken internal links
  • 301 redirect: Point deleted pages to relevant alternatives
  • Fix the link: Update internal links pointing to the wrong URL
  • Custom 404 page: Create a helpful error page with search functionality and popular links

Why It Matters for SEO

Every 404 error on a page that previously ranked or had backlinks represents lost SEO value. The link equity from external backlinks pointing to a 404 page is completely wasted. Additionally, excessive 404 errors consume crawl budget that could be spent indexing valuable pages. Regular monitoring and fixing of 404 errors is a fundamental part of technical SEO maintenance. Use Google Search Console to monitor 404s.