404 SEO
A 404 is an HTTP status code that tells browsers and search engines a requested URL was not found on the server.
Key takeaways
- A 404 is a normal HTTP response, not a penalty.
- Only fix 404s on important URLs (backlinks, sitemap, internal links).
- Redirect with 301 to the most relevant page, never to homepage.
- Do not block 404s with robots.txt.
- A custom 404 page improves user experience.
For SEO, 404s matter mainly when they affect important URLs, internal links, sitemaps, or pages with backlinks.
Example
A user clicks a link to example.com/old-product but the product was discontinued. The server returns a 404 status code. The browser shows a "Page Not Found" message. If the page had backlinks, those links lose value unless redirected.
When should I use this?
Use a 404 when:
- Content is permanently removed and no suitable replacement exists.
- A URL was never valid (typo, broken link).
- You intentionally want to signal that a page is gone without redirecting.
Do NOT use 404 when:
- The content still exists at a new URL (use 301 redirect).
- You want to keep link equity (redirect instead).
What it is not
- A penalty or negative ranking signal from Google.
- A reason to block the URL in robots.txt (that causes crawl errors).
- Always a problem — most 404s are harmless.
- An excuse to redirect all 404s to the homepage.
Quick start
- Find 404s – Use Google Search Console (Coverage report) or a crawler like Screaming Frog.
- Categorize – Mark each 404 as: has backlinks, in sitemap, linked internally, or obsolete.
- Fix important ones – For URLs with backlinks or in sitemap: redirect to the most relevant page using a 301.
- Leave obsolete ones – If a URL has no value, let it stay 404 (or use 410 if permanently gone).
- Create a custom 404 page – Help users find alternatives with navigation, search, or suggested pages.
Common mistakes
- Redirecting every 404 to the homepage instead of the most relevant destination.
- Leaving broken internal links and sitemap URLs unchanged after removing or moving content.
- Using robots.txt to hide 404 URLs rather than letting them return proper status codes.
- Treating all 404s as SEO problems even when the URL is obsolete and has no value.
Next step
FAQ
Should I fix every 404 on my site?
No. Google says most 404s are harmless. Only fix those on important URLs: pages with backlinks, in your sitemap, or linked internally.
What is the difference between 404 and 410?
Both mean the page is not found. A 410 explicitly says the content is gone permanently; a 404 is more neutral. Google treats them similarly.
Can a 404 hurt my rankings?
Not directly. But if a page with valuable backlinks returns 404, you lose link equity. Redirect it with a 301 to a relevant page.
Related topics
Sources
- Google Search Console Help: 404 (Page Not Found) errors — Best source for Google’s guidance on when to fix, redirect, or leave 404s.
- Google Search Central — Official documentation on HTTP fetching and how Google handles crawl errors and status codes.
- RFC 9110 — Defines the HTTP 404 status code at the protocol level.
- Google Search Central: Site move with URL changes — Useful for canonical redirect practice when URLs change.
Reviewed by Lucía Marín, Founding editor.