404 Not Found (Not Found Error) is the HTTP status code indicating that the URL requested by a user or bot could not be found on the server. It is typically returned for deleted pages, mistyped URLs, or broken links.
Key SEO points about 404s:
- A small number of 404s is normal; a site is constantly evolving.
- A large number of 404s negatively affects site health signals.
- If a page with backlinks becomes a 404, it results in a serious loss of authority.
- If an indexed page returns a 404, Google will remove it from the index after a while.
Best practices for 404 management:
- Redirect 404 pages that have backlinks or bring in organic traffic to the closest relevant page with a 301
- Design a custom 404 page: search box, category links, popular content suggestions
- Regularly check the “Pages > Not found (404)” report in Search Console
- Find and fix internal 404 links using a crawling tool
Tip: Your 404 page must return a real 404 HTTP status code. Pages that display a “Page not found” message but return 200 OK are treated as “soft 404s,” and Google does not like them.