Finding, assessing and fixing 404 errors

What is a 404 error?

The status code 404 “Not Found” says that the server found nothing at the requested URL. That is how the HTTP standard RFC 9110 describes it. The code does not reveal whether the condition is temporary or permanent. For content that has been permanently removed, the standard provides the code 410 “Gone”.

404, 410 and soft 404

What does the page show, and what does the server send?

An error page can display “Page not found” and still send status 200. Only the server's response shows the real status code. This is how you check it in the terminal.

The first line must say 404 or 410. If it says 200 or 301, you are looking at a soft 404 or a redirect. To check many URLs at once, use the HTTP Status Code Checker.

Do 404 errors hurt your SEO?

Individual 404 errors do not harm the rest of the website. Google has been saying since 2011 that 404 errors on their own do not count against a website. According to the current documentation, Google treats all 4xx codes except 429 the same way. URLs that are already indexed drop out of the index, and Google gradually fetches them less often.

That is why Search Console Help recommends fixing above all the 404 errors you link to yourself or that are listed in your sitemap.

Finding 404 errors

Three sources each show a different part of the picture. GA4 shows which 404 pages real visitors open and where they come from. Search Console shows what Googlebot finds, and a crawl checks every internal link.

With Google Analytics 4

GA4 only records 404 pages if the error page is set up correctly. The easiest way is to filter an exploration by the page title of the error page and add the page referrer. This shows you which URL leads nowhere and which page the link is on. If the error page has no unique title, you send a custom page_not_found event. The setup with Tag Manager or gtag.js and the explorations for internal and external 404 errors are explained step by step in the guide Finding 404 errors with Google Analytics 4.

With Search Console

In the Page indexing report, “Not found (404)” lists the URLs that responded with 404 when Google crawled them. Alongside it there is the reason “Soft 404”. The report only shows URLs that came up in the last month. After a fix, use URL Inspection and the live test to check what Google now sees. Where the other crawl errors are is explained in the guide Crawl errors in Search Console. The other reasons in the report are covered in the Google indexing guide.

With a crawl

A crawl follows all internal links and the URLs from your sitemap. It also finds 404 errors on pages nobody has visited yet, for example right after a release. Combined with Search Console data, you can see straight away which affected URLs had clicks before.

Assessing 404 errors

Before you change anything, sort the list by impact.

1. URLs with clicks from Search Console or revenue in GA4.
2. URLs with backlinks from other websites.
3. URLs that your own pages or the sitemap link to.
4. The rest, such as old campaign URLs without links or visits, can stay 404.

Fixing 404 errors

External links need a judgment call. If a link from another site points to a URL that never existed on your website and brings no visitors, the URL can stay a 404. If the link brings visitors or the URL has backlinks, a redirect is worth it. Google gives the example of a typo in an external link, which you redirect to the correct URL with a 301. For important links, you can also ask the linking website to correct the link. When a 301 or a 302 fits is explained in the guide 301 and 302 redirects.

A good 404 page

The error page stays on the requested URL and sends status 404. It says in one sentence what has happened and offers search, navigation and links to the most important sections.

Common mistakes

• All unknown URLs redirect to the homepage. Google treats this as a soft 404.
• The error page returns status 200.
• On a server-rendered website, the error page redirects to /404/ and so leaves the requested URL. For single-page apps, Google describes the JavaScript redirect to a URL with a server 404 as one of two options.
• Internal links permanently point to redirects. How to find them is covered in the guide Testing redirects.

FAQ