404 Not Found

What it means

HTTP 404 Not Found means the server could not find anything matching the requested URL. The resource may have been deleted, moved without a redirect, or the URL may simply be wrong. The server gives no indication whether the absence is temporary or permanent.

When it happens

It happens with broken or mistyped links, deleted pages with no redirect, changed URL structures, or links from other sites pointing to URLs that no longer exist.

How to fix it

• If the page moved, add a 301 redirect to the new URL.
• Fix internal links and update any incorrect URLs you control.
• Restore the page if it was deleted by mistake.
• Return a clear, helpful 404 page that links back to working sections of the site.
• If the page is gone for good and should not be redirected, consider returning 410 instead.

SEO impact

A normal part of the web in small numbers. Search engines drop 404 URLs from the index, which is fine for genuinely missing pages. Problems arise when valuable pages 404 unintentionally (losing rankings and link equity) or when broken internal links waste crawl budget. Redirect valuable lost URLs; let truly dead ones 404 or 410.