Anyone who runs a website will come across them sooner or later: pages that no longer exist but are still requested. The result is a 404 error. This article explains what exactly is behind it, why it matters for SEO and how to handle it properly.
What is a 404 error?
A 404 error is an HTTP status code that a web server returns when a requested page cannot be found. HTTP status codes are three-digit numbers that servers use to tell the browser (or a crawler) what happened to a request. The 4xx codes stand for errors on the client side, meaning requests that the server receives but cannot fulfill.
In the case of the 404 code, this means specifically: the server can be reached, but the requested URL does not exist at this address. This may be due to a deleted page, a changed URL or simply a typo in the address bar.
How do 404 errors occur?
404 errors almost always occur when a URL is requested that used to exist or never existed. The most common causes are:
- Deleted pages without a redirect: A product page or a blog article is removed without a redirect being set up. All existing links to this URL lead nowhere.
- URL changes during relaunches: When a website is restructured, URL structures often change. Without clean redirects, this produces 404 errors in large numbers.
- Typos in internal links: One incorrectly set internal link is enough to make a page unreachable for users and crawlers.
- Broken external links: Other websites link to a URL that no longer exists.
Broken internal links in particular are a frequently underestimated problem. A regular link audit helps to uncover such sources of error systematically before they have a negative effect on rankings and user experience.
Soft 404 vs. real 404: what is the difference?
Not every error page is technically a 404. There is an important distinction that is particularly relevant for SEO.
A real 404 occurs when the server responds to a request with the HTTP status code 404. This clearly signals to browsers and crawlers: this page does not exist.
A soft 404, by contrast, is a page that is empty or meaningless in terms of content but still returns the status code 200 to the server, in other words signals “everything is fine”. This happens, for example, when a product page is technically reachable but no longer shows a product because the item is sold out or has been removed from the range.
Google recognizes soft 404s and treats them much like real 404 errors, even if the status code is formally correct. That makes soft 404s particularly treacherous, because they often remain invisible in standard crawls.
What impact do 404 errors have on SEO?
404 errors are not automatically an SEO problem. Google itself communicates that a 404 error on a page that was never meant to rank is no cause for concern. Nevertheless, there are scenarios in which 404 errors do real damage.
Lost link power: When external websites link to a URL that now responds with 404, the link equity of these backlinks is lost. This is especially painful when the links are high-quality ones.
Wasted crawl budget: Googlebot has a limited crawl budget for every website, that is, a certain number of pages it visits per crawl run. Many 404 URLs can cause the crawler to waste time on dead pages instead of crawling relevant content.
Poor user experience: Users who land on a 404 page often leave the website immediately. This increases the bounce rate and can, in the long term, generate signals that have a negative effect on rankings.
All of these are topics that fall directly into the field of technical SEO, because they concern the technical foundation on which search engines evaluate and crawl a website.
Finding 404 errors: how to proceed
Before you can fix 404 errors, you need to know where they are hiding. There are several proven methods for this.
Google Search Console: The coverage report (or the page indexing report) in Google Search Console lists all URLs that Google found with a 404 error while crawling. This is the most direct way to see which pages cannot be reached from Google’s perspective. Since Search Console is closely connected to Google indexing, it is worth keeping an eye on both reports regularly.
Screaming Frog: The desktop tool crawls your entire website and returns the HTTP status code for every URL. This way you find not only 404 errors but also the broken internal links that lead to them.
Ahrefs or SISTRIX: These tools additionally show which external backlinks point to 404 URLs. This is particularly valuable because it lets you identify link power that you can win back through a redirect.
Figure 1: 404 pages in GSC under “Pages -> Not found 404”
Fixing 404 errors: restore, redirect or remove?
Not every 404 error calls for the same response. The right decision depends on why the page no longer exists and whether it still has link power or traffic potential.
Restore the page: If a page was deleted by mistake or still has search volume, restoring it is the best option. The content is preserved, and existing rankings can recover.
Set up a 301 redirect: If a page has moved permanently to a new URL or thematically similar content exists, redirect the old URL to the new one with a 301 redirect. A 301 redirect signals to Google that the page has been moved permanently and passes on most of the link power in the process.
Set a 410 status code: If a page was removed deliberately and permanently and there is no sensible redirect target, a 410 status code is the cleaner solution than a 404. The 410 code explicitly signals to Google that the page was removed on purpose, which gets the crawler to remove the URL from the index more quickly.
It is also important to check your own XML sitemap regularly and make sure it contains no URLs that respond with 404. A sitemap with dead URLs sends contradictory signals to Google.
Figure 2: Decision tree for 404 errors.
How to design a good 404 page
Even though you should avoid 404 errors as far as possible, you will never be able to eliminate them completely. That is why it is worth designing the 404 page itself in such a way that users do not simply leave but stay on the website.
A good 404 page contains at least the following elements:
- A clear explanation: Tell the user briefly and understandably that the page they were looking for was not found. No technical jargon.
- A search function: If users do not find what they are looking for, give them the option to search directly on the website.
- Links to important pages: A navigation or a selection of relevant pages (e.g. home page, categories, popular articles) helps users find the right thing quickly.
- Matching design: The 404 page should stay in the corporate design of the website. Users should notice that they are still on the right website.
Humor or creative design can work but are not a must. What matters is that the page is useful and does not lead the user into a dead end.
Conclusion
404 errors are part of everyday life for every website, but how you deal with them makes the difference. If you track them down regularly, fix them consistently and design your own 404 page sensibly, you protect both rankings and user experience. Especially after relaunches or major structural changes, a systematic pass through all affected URLs is worthwhile.
If you need support with the technical analysis of your website or want to know how 404 errors affect your organic performance, you can send us a no-obligation inquiry.
