404 Not Found — What It Means and How to Fix It

What 404 means

The best-known status code. The server reached a decision and the answer is that nothing lives at this path. Importantly, 404 says nothing about whether the resource ever existed or might exist later — the server is deliberately not telling you.

Common causes

•A genuinely wrong or mistyped URL.
•A page moved or deleted with no redirect left behind.
•A routing rule that does not match — a missing trailing slash is a classic.
•A deploy that did not copy every expected file.
•Case sensitivity differences between a local machine and a Linux server.

How to fix it

Confirm whether the path exists on disk or in the router. If a page moved, return a 301 to the new location rather than a 404 — for anything with inbound links or search traffic, a redirect preserves value that a 404 discards. Case sensitivity catches people constantly when developing on macOS and deploying to Linux.

Catching 404 before your users report it

A 404 on a URL that used to work is a deploy problem, not a traffic problem, and it will not show up in an uptime check that only looks at your homepage. Monitor the specific URLs that matter.

Monitor for 404 responses free

Often confused with

403 Forbidden

← All HTTP status codes

404 Not Found — questions

Do 404 errors hurt SEO?

A 404 on a page nobody links to is harmless and completely normal. A 404 on a page with inbound links or existing rankings wastes that value — redirect it. What actually causes damage is returning 404 for pages that should exist, or returning 200 for pages that do not.

What is a soft 404?

A page that returns HTTP 200 while displaying "not found" content. Search engines treat this as a bug because the status line and the page contradict each other. Return a real 404 status for missing pages.

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