You have seen a 404 page before — "Page Not Found", often with an apology and a search box. From a user's perspective it is frustrating. From an SEO perspective, 404 errors range from completely harmless to genuinely damaging depending on where they occur and what was linking to them.

Quick Answer: A 404 error means the server cannot find the requested page — the URL exists but the page at that address does not. 404 errors hurt SEO when important pages with backlinks or strong internal links return them, because link equity is lost. Random 404s from broken external links pointing to non-existent pages on your site have minimal impact. Fix 404s on pages that had value; ignore or let Google deindex the rest.

What exactly causes a 404 error?

A 404 error is an HTTP status code meaning "Not Found". Your server returns this code when someone requests a URL that does not match any page in your site's file structure or database. Common causes include:

  • A page you deleted without setting up a redirect
  • A URL you changed without redirecting the old address
  • A typo in an internal link pointing to a URL that does not exist
  • An external website linking to an old URL on your site that no longer exists
  • A CMS migration where URL structures changed

Is a 404 error the same as a soft 404?

No — a hard 404 returns an actual 404 HTTP status code. A soft 404 returns a 200 OK status code (meaning the server thinks the page is fine) but displays "page not found" style content. Soft 404s are more problematic for SEO because Google may index the error page as real content, creating thin pages in your index. Google's Search Console flags both types in the Coverage report.

When do 404 errors actually damage SEO?

Not all 404 errors matter equally. The ones that cause real SEO damage are:

  • Pages that had backlinks pointing to them — when a linked page returns 404, all the link equity from those backlinks is lost. The more backlinks the page had, the more damaging the 404.
  • Pages that ranked for valuable keywords — a previously ranking page that disappears takes its ranking signals with it. Without a redirect, that traffic is gone.
  • Pages heavily linked internally — internal links passing equity to a 404 page waste that authority rather than directing it to live content.
  • Large numbers of 404s from a migration — if a site rebuild creates hundreds of 404s simultaneously, the cumulative crawl budget waste and equity loss can significantly suppress rankings site-wide.

When are 404 errors harmless?

404 errors that have no real SEO impact include:

  • URLs that never existed on your site and have no backlinks (random bot traffic to guessed URLs)
  • Old URLs from years ago with no backlinks and no indexing history
  • 404s for resources like missing images or JavaScript files that were never pages

Google has confirmed that 404 errors alone do not penalise your site. The concern is the indirect effects — lost equity, wasted crawl budget — not the 404 status itself.

How do you find all 404 errors on your site?

Use our broken link checker to scan your entire site and identify every URL currently returning a 404 status. The report shows both the broken URL and which page on your site contains the link to it — giving you exactly what you need to fix each one. Also check Google Search Console → Coverage → Not Found (404) for a complete picture including 404s Google has encountered while crawling.

How do you fix a 404 error?

The fix depends on the situation:

  1. The page was moved or renamed — set up a 301 redirect from the old URL to the new URL. This preserves link equity and fixes user experience simultaneously.
  2. The page was deleted but had backlinks — either restore the page or 301 redirect to the most relevant live alternative page.
  3. An internal link points to a non-existent URL — update the internal link to point to the correct current URL.
  4. The page is genuinely gone with no replacement — return a proper 404 (or 410 Gone if it will never return) and let Google deindex it naturally.

What is the difference between a 404 and a 410 status code?

A 404 means "not found" — Google may check back periodically. A 410 means "gone permanently" — Google removes it from the index faster. Use 410 when a page is genuinely removed forever with no replacement planned. Use 404 when there is any chance the page might return.

Summary

  • 404 errors mean a page cannot be found — they range from harmless to damaging depending on the page's value
  • 404s on pages with backlinks or rankings cause real equity loss — fix these with 301 redirects immediately
  • Random 404s from bot traffic or links to non-existent pages have minimal impact
  • Find all 404s with our broken link checker and Search Console Coverage report
  • Fix with 301 redirects for moved content, updated internal links for typos, or 410 for permanently deleted pages

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