TECHNICAL SEO
404 error: what it means and when to fix it
The Not Found response for a URL with no page; correct for dead URLs, a problem only for ones that matter.
- Beginner level
- 2 primary sources
- Reviewed 29 October 2026
- TopicTechnical SEOAlso in SEO auditing & troubleshooting
- LevelBeginnerNo background needed
- Also called404, page not found
- Sources2 primary sourcesGoogle Search Central, Search Console Help
- Reviewed29 October 2026Re-checked every 12 months
On this page
Quick definition
A 404 error is the HTTP 404 Not Found response a server returns when no page exists at the requested URL. It is the correct answer for URLs that should not exist, and only needs fixing when visitors, links or search engines expect a real page there.
Why it matters
404s matter in three cases: an important page returns one by mistake, a removed page still has valuable backlinks or traffic, or internal links point at it and send visitors into dead ends. Outside those cases, 404s are normal. Search Console lists them so you can check, not because each one is an error.
What to do with a 404
| Situation | Response |
|---|---|
| The page moved | 301 to the new URL |
| Removed, with a close replacement | 301 to the replacement |
| Removed, no replacement | Keep 404, or 410 to say it is gone on purpose |
| Never existed (typos, junk URLs, scanners) | Keep 404; no action |
| Internal links point to it | Fix the links, whichever response you choose |
Google treats 404 and 410 almost the same; 410 can be marginally faster to drop. A helpful 404 page, with search and links to main sections, keeps visitors on the site, but it must still return the 404 status.
Example
A real estate portal expires 3,000 sold listings a month. Each expired listing returns 404. That is reasonable: the property is gone. The portal checks two things instead of redirecting all of them: listings with external links are redirected to the matching neighbourhood page, and the site’s own "recently viewed" widget stops linking to expired listings.
How to check it
Common mistakes and misconceptions
Myth 404s hurt the rankings of the rest of the site.
In fact Google has said 404s on URLs that should not exist do not harm the site’s other pages.
Myth Every 404 should redirect to the homepage.
In fact Mass homepage redirects are treated as soft 404s and frustrate visitors. Redirect only to genuine equivalents.
Check it on your site
Free tools, no sign-up
- FreeBroken Internal Link CheckerCrawl up to 50 pages of a site and list internal links that lead to errors or redirects, with the pages that link to them.Open the tool
- FreeBulk HTTP Status CheckerCheck up to 25 URLs at once: status code, final URL after redirects, number of redirects and response time.Open the tool
- FreeExternal Link Status CheckerCheck whether the links on a page to other sites still work, redirect or are broken.Open the tool
In the NdovuSEOLabs platform
Run the same checks on every page of your site, with your own data.
Sources and review
- How HTTP status codes, and network and DNS errors affect Google Search Google Search Central
- Page indexing report Search Console Help
Written and maintained by Ndovu SEO Labs. First published 29 October 2026. Facts last checked against the sources above on 29 October 2026. How we write and review the glossary.