GlossarySEO
What is a 404 error?
Also called: 404 not found, 404 page, broken link
Definition
A 404 error is the HTTP status a server returns when a requested URL doesn't exist. Search engines drop 404 URLs from their index, and a 404 on a deleted page is normal, not a penalty.
404 error, explained
A 404 Not Found means the server understood the request but has nothing at that address. It happens when a page is deleted, a URL is mistyped, or someone links to a path that never existed. Every site has some 404s, and many come from links you don't control.
Google's documentation is calm about them. If a URL returns 404, the indexing pipeline removes it from the index if it was indexed, and newly found 404 URLs aren't processed. Search Console's Page indexing report says 404 responses aren't necessarily a problem if the page was removed without a replacement. Googlebot will keep retrying a 404 URL for some time, and there's no way to stop that, which is why you still see old URLs in reports months later.
The problem cases are specific. A page that moved should get a 301 to its new home, not a 404, or you throw away its links and rankings. A page you want indexed that returns 404 by accident, often after a deploy changed a route, is a real bug. And internal links pointing to 404s waste crawls and frustrate visitors, so fix those at the source.
A good 404 page returns the actual 404 status, explains what happened, and links to the homepage, search or your main sections. It should never redirect everything to the homepage, which Google may treat as a soft 404 anyway.
Why it matters for founders
Founders often panic when Search Console lists hundreds of 404s. Most are harmless. The ones worth fixing are moved pages that lost their redirect and internal links you can update in minutes.
Example
After renaming your blog URLs, Search Console shows 40 new 404s. Ten of them have backlinks from other sites. You add 301 redirects for those ten, update your internal links, and leave the rest as 404s.
Common mistakes
- Redirecting every 404 to the homepage.
- Returning
200on the 404 page, which creates soft 404s. - Leaving internal links and sitemap entries pointing at deleted URLs.
- Treating every 404 in Search Console as an emergency.
Sources
- Google Search Central: How HTTP status codes and network errors affect Google Search
- Search Console Help: Page indexing report
Checked
Related terms
- Soft 404A soft 404 is a page that looks like an error or empty page to Google but returns a success code (
200) instead of404. Google treats it as not found and reports it in Search Console. - 410 Gone410 Gone is an HTTP status that says a URL was removed on purpose and won't come back. For Google Search it works almost exactly like a 404: the URL is dropped from the index.
- HTTP status codeAn HTTP status code is the three-digit number a server sends back with every response, like
200,301,404or503. It tells browsers and crawlers whether the request worked, moved, failed or should be retried. - 301 vs 302 redirectA 301 redirect says a page has moved permanently, so search engines should treat the new URL as canonical. A 302 says the move is temporary, so they keep showing the original URL.