What is a 404 Error? Definition & How to Fix It

Definition

A 404 error (also called "404 Not Found") is an HTTP status code returned by a web server when the requested page does not exist. It means the server is reachable, but the specific URL the user or search engine tried to access cannot be found.

Common causes of 404 errors

• Deleted pages — a page was removed without setting up a redirect.
• Changed URLs — the page was moved to a new URL, but the old URL was not redirected.
• Typos in links — an internal or external link contains a misspelled URL.
• Expired content — product pages, event pages, or temporary content that no longer exists.
• Broken external links — another website links to a URL on your site that no longer works.

SEO impact

404 errors themselves are not a direct ranking penalty — Google has confirmed this. However, they have indirect effects that can hurt your search performance:

• Wasted crawl budget — search engine crawlers spend time on pages that return errors instead of indexing your real content.
• Lost link equity — if external sites link to a 404 page, you lose the ranking value those backlinks would have provided.
• Poor user experience — visitors who land on a 404 page are more likely to leave your site, increasing bounce rate.
• Broken internal linking — 404 errors in your internal link structure prevent link equity from flowing to important pages.

How to find 404 errors

The fastest way to find 404 errors on your website is to run a broken link scan. Broken Link Scan crawls your entire site and reports every URL that returns a 404 status code, along with the source pages where those broken links appear. You can scan up to 500 pages for free with no signup required.

You can also check Google Search Console's "Pages" report under the "Not found (404)" category, though this only shows pages Google has attempted to crawl — it may miss broken links that exist in your site's navigation or content.

How to fix 404 errors

1. Set up 301 redirects — if the content moved to a new URL, create a 301 redirect from the old URL to the new one.
2. Update internal links — fix any links on your own site that point to the 404 URL.
3. Restore the page — if the content was removed by mistake, restore it.
4. Return a proper 410 — if the content is permanently gone and has no replacement, a 410 (Gone) status code tells search engines the removal is intentional.
5. Create a useful 404 page — design a custom 404 page that helps visitors find what they were looking for.

Regular monitoring is the best way to prevent 404 errors from accumulating. Learn more about finding and fixing broken links, or scan your site now to see if you have any 404 errors.