404 Error
Traditional SEO
A 404 error is an HTTP status code indicating that the requested page could not be found on the server, typically because it was deleted, moved without a redirect, or the URL was typed incorrectly.
Definition
A 404 error is an HTTP status code indicating that the requested page could not be found on the server, typically because it was deleted, moved without a redirect, or the URL was typed incorrectly. From a search perspective, 404 errors on pages that previously ranked mean those pages are no longer visible in search, and any backlinks pointing to those URLs are now pointing to nothing. From a user perspective, landing on a 404 page is a dead end that typically results in the visitor leaving.
How It Works
When a user or search crawler requests a URL and the server cannot find a matching page, it returns a 404 status code. Google's crawlers track 404 responses. Pages that consistently return 404 are removed from the index. If that page had accumulated backlinks and ranking authority, that authority is lost unless a 301 redirect is in place to transfer it to a new URL.
Soft 404s are a related issue: pages that return a 200 OK status code but display a "not found" message or nearly empty content. Google can detect these and treat them similarly to true 404s.
Why It Matters
404 errors are a common, fixable source of SEO loss. Sites that have been around for years often accumulate dozens or hundreds of broken internal links and orphaned URLs from old pages that were deleted without redirects. Each one represents authority that is not flowing anywhere useful. A technical SEO audit typically surfaces these, and fixing them through redirects or by correcting internal links is a concrete way to recover lost value.
Example
A marketing consultant relaunches her website with a new URL structure. Dozens of old blog post URLs now return 404 errors. Those posts had earned backlinks from industry publications. After implementing 301 redirects from each old URL to the most relevant page on the new site, the authority those backlinks carried begins flowing to the new pages, and rankings start recovering within four to six weeks.
Related Terms
301 Redirect, Technical SEO, Crawl Budget, Backlink, Robots.txtIf you are working on your business's search visibility and want a practical starting point, the AI Workflow Audit includes a review of your current content and search presence. Calculate how much slow follow-up costs your business while you are at it.
Related terms
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