What Is a 404 Not Found Error?
A 404 error means the server could not find the page or file you requested. This is usually caused by a broken link, a deleted page, or an incorrect URL. While a single 404 is not harmful, many 404 errors can hurt your SEO and frustrate visitors.
Common Causes
- Deleted or moved content – The page existed at one point but has since been removed or relocated without a redirect.
- Typographical error in the URL – A misspelled link in your navigation, footer, or an external site pointing to a wrong path.
- Permalink structure change – If you changed your CMS permalink settings, old URLs will break unless redirects are in place.
- Missing file upload – An image, CSS, or JavaScript file referenced in your HTML was never uploaded or was accidentally deleted.
How to Fix It
- Verify the URL – Double-check the address bar for typos. URLs are case-sensitive on Linux servers, so
/Aboutis different from/about. - Flush permalinks – In WordPress, go to Settings > Permalinks and click Save Changes without modifying anything. This regenerates the
.htaccessrewrite rules. - Set up 301 redirects – If a page has permanently moved, add a redirect in your
.htaccessfile:Redirect 301 /old-page /new-page. - Check file existence – Use File Manager or FTP to confirm the file physically exists at the expected path.
- Create a custom 404 page – Add
ErrorDocument 404 /404.htmlto your.htaccessand design a helpful page that guides visitors back to working content.
Finding Broken Links
Use a free tool like Broken Link Checker or Google Search Console to scan your site for all 404 errors. Fix each one with either corrected links or 301 redirects. Keeping your site free of 404 errors improves both user experience and search engine rankings.