404 Not Found means the origin server did not find a current representation of the target resource, or is not willing to disclose that one exists. It does not say whether the absence is temporary or permanent; use 410 Gone when you know the resource is gone for good.
A 404 is heuristically cacheable, so CDNs and browsers may cache it for a while unless told otherwise. A good 404 page explains the problem and offers navigation or search, but it must still be served with the 404 status.
404 is by far the most common error in link and redirect checks: broken internal links, mistyped URLs, deleted products and redirects that point to a URL that no longer exists.
Example response
HTTP/1.1 404 Not Found
Date: Fri, 06 Nov 2026 10:15:32 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 115
Cache-Control: public, max-age=300
<!doctype html>
<title>Page not found</title>
<h1>Page not found</h1>
<p>The page you requested does not exist.</p>SEO and redirect checking
404s are a normal part of the web and do not hurt a site's ranking by themselves. Google stops indexing URLs that return 404 and drops them over time, but it re-crawls them now and then in case they come back. The problem is important URLs that return 404, because they lose their traffic and the value of the links pointing to them. Redirect moved content to its new URL with a 301 instead.
Do not redirect every missing URL to the homepage, because Google may treat such redirects as soft 404s. A "page not found" message served with status 200 is a soft 404 too. The Bulk Redirect Checker and Sitemap Redirect Checker find URLs that end in a 404.
Common causes and use cases
- A page was deleted or moved without a redirect.
- A broken or mistyped link, on your own site or on another one.
- A redirect points to a URL that does not exist (a broken redirect target).
- Letter case or trailing slashes differ, for example
/Pageversus/page, or/page/versus/pageon a server that treats them as different URLs.