The 404 error – how does it affect SEO?

The 404 error, also known as "404 Not Found", is one of the most commonly encountered HTTP error codes. It means the server did not find the file or web page the user was looking for. Most often that happens because of a typo in the URL, a deleted page or a page moved to another address without a proper redirect. In this article we explain what a 404 error actually is, what causes it, how it affects search engine optimisation and how it can be fixed.

What is a 404 error?

Displaying web pages is a complex mechanism that begins when a user types a URL into a browser. The browser then establishes a connection with the server hosting the requested page. That connection involves sending an HTTP (HyperText Transfer Protocol) request containing information about the resource the user wants to view.After receiving the request the server analyses it and tries to find the matching file or page in its database. In reply the server sends an HTTP header containing a status code reporting the outcome of that process. If the server cannot find the resource – for example because of an incorrect URL, a deleted page or a missing redirect to a new location – it returns a 404 error code.The 404 error code is a particular kind of HTTP response telling the user the requested resource was not found. It consists of three digits, each with its own meaning:

• The first digit (4): Indicates the problem lies on the client side, meaning the error stems from an incorrect request sent by the browser. That may be a typo in the URL, an outdated link or no access to the page.
• The middle digit (0): Means this is a general error. In this context it points to a general problem with the request that prevents the server from processing it correctly.
• The last digit (4): Reports that the server did not find the requested resource. It is the final confirmation that the requested page or file does not exist at the given address.

Why are 404 pages needed?

Although a 404 page is in theory a page that does not exist, it serves an important substitute function. When a user makes a typo in a URL, the 404 page tells them the requested resource was not found instead of showing a server error or another unfriendly message. 404 pages can be designed to be user-friendly, containing links to other parts of the site, an internal search or suggestions of popular content.

How 404 errors affect SEO

Although Google says occasional 404 errors have no direct effect on a page's position in search results, their frequent appearance can have serious SEO consequences. Here are the key aspects:

1. Losing traffic:
   • When users hit 404 errors they may start seeing the site as less credible or out of date.
   • That can lead to negative opinions and fewer visits.
   • A high bounce rate caused by frequent 404 errors can signal to search engines that the site does not meet users' expectations.
2. Losing backlink value:
   • Links pointing at non-existent pages stop passing SEO value.
   • Any external links that could improve the site's authority become useless.
   • The site loses the authority it could gain from valuable backlinks.
3. Wasted crawl budget:
   • 404 pages needlessly consume crawl budget.
   • Other, more valuable pages may not be indexed or updated in time.
   • That affects the site's visibility in search results.
4. Disrupting the internal linking strategy:
   • The internal linking structure is key to SEO, because it helps Google understand the hierarchy and importance of individual pages.
   • When internal links lead to 404 errors, the whole linking strategy can be disrupted.
   • That leads to lower SEO effectiveness.
5. Technical overhead:
   • Constantly monitoring and managing 404 errors takes resources, both time and money.
   • Tools such as Google Search Console help identify these problems.
   • Regularly analysing and fixing errors is extra effort that could go into other SEO work.

How do you fix 404 errors?

To minimise the negative SEO impact of 404 errors, it is worth implementing a comprehensive plan covering several key steps:

1. 301 redirects:
   • When a page is moved or deleted, you should set a 301 redirect from its old URL to the new address. This kind of redirect preserves the original page's SEO authority and passes it to the new page, ensuring users and search engine crawlers reach the right content.
   • 301 redirects are especially important when changing a site's structure, updating a CMS or reorganising content, helping maintain consistency and availability of information.
2. Regular error monitoring:
   • Tools such as Google Search Console are invaluable for monitoring a site's condition regularly. They allow 404 errors to be detected quickly so they can be fixed immediately.
   • Monitoring should cover both main pages and subpages to identify any problems that may affect users and SEO.
3. Fixing backlinks:
   • An important step is contacting the owners of other sites linking to your 404 pages and asking them to update or correct the broken links.
   • You can also use backlink monitoring tools to identify and fix problems with non-existent pages quickly.
4. Using friendly 404 pages:
   • 404 pages should be designed to be user-friendly. They should contain useful information such as links to popular content, an internal search or suggestions of alternative pages.
   • Adding humorous or visual elements can soften users' negative feelings and encourage them to keep exploring the site.
5. Updating the sitemap:
   • Regularly updating the sitemap and submitting it to Google Search Console helps search engines understand your site's structure better and identify deleted or moved pages faster.
   • With an up-to-date sitemap, search engine crawlers can index your content more efficiently, minimising the risk of 404 errors.
6. Using analytics tools:
   • Analytics tools such as Google Analytics can help identify pages with a high bounce rate, which may signal problems with 404 errors.
   • Analysing user behaviour on 404 pages lets you understand their needs and expectations better, which can lead to optimising those pages and improving the user experience.

Summary

The 404 error is an unavoidable part of managing a website, but its negative effects can be minimised through regular monitoring and the right countermeasures. 301 redirects, correct linking and friendly 404 pages can help maintain a positive image for the site and keep its SEO strong. As a result users will have a better experience with your site.