Sometimes, when we click on a link, we encounter a strange page with a number 404 or "404 Error" or "Page not found" or other wordings indicating that something went wrong. These are called "dead links" and can be frustrating for both users and website owners. Let's briefly explain why and how this happens.

How does a 404 error occur?

The number 404 appears whenever the webpage does not exist and, therefore, is not accessible.

It is a standardized HTTP status code sent by the web server of an online platform to the browser (also known as the client). There are over 60 HTTP status codes that the server can use to respond to an HTTP request, categorized into 5 (or technically 6) groups (more on that later). The 404 status code is the most well-known, as it is encountered by the average user. Most HTTP status codes are processed in the background and not displayed to the user.

Reasons why a webpage is not accessible:

• The webpage/URL and its content have been deleted and no longer exist.
• The content is available under a different URL, but the links have not been updated.
• A typographical error in the linking on the source page.
• The responsible web server is temporarily unreachable, or the connection has been interrupted.
• The domain name cannot be converted to an IP address.
• The webpage never existed, and it is simply a typographical error in the browser window.

How can the 404 error be resolved?

Encountering a 404 error can be frustrating, and the temptation to leave the webpage quickly is strong. However, the desired information may still be available.

The following solutions can help:

1. Refresh the webpage in the browser or reload it using [F5].
2. Check the URL: The person who created the link may have made a typo when linking. Typos, such as forgetting a forward slash, can happen easily.
3. Use a search engine: Simply search for the desired webpage using a search engine. This will likely display the correct URL.
4. Clear cache and cookies: Often, old data is stored, and it's possible that the webpage was previously accessed with an outdated link. By clearing the browser's cache and cookies, these outdated data are removed, and the desired page may become accessible again.
5. Contact the website owner: Lastly, it can be helpful to contact the operator of the website and inform them that the webpage is no longer accessible. They may also provide information on whether the content indeed no longer exists. Website owners appreciate such information, as 404 errors are not favorable for search engines.