What is a 404 Bad Request Error and How to Fix it?

Alliance  ·  December 07, 2020

A 404 Bad Request Error is a type of server response code. When browsing a website, there is an ongoing client server interaction, which at times can be broken due to a bad server response. The server will generate a response as to whether a request is successful or not by displaying an HTTP status code, which at times might display as a 404 Bad Request Error. In this article, we will explore why 404 Bad Request Errors occur and how to fix them.

What is an HTTP status code?



When a client makes a request to a server, an HTTP status code is generated as a response to that request. There are five different types of HTTP status codes that are generated as a server response. The first digit of the status code is categorized as the class of the response by the server, so it is most important to pay attention to this part of the status code. Below are a list of HTTP status codes: 

  • 1xx : informational response, request is currently processing
  • 2xx: successfully understood and completed request
  • 3xx: redirection request, will require further action to be taken
  • 4xx: bad syntax error, request cannot be processed
  • 5xx: server error and failure to complete request

What is a 404 Bad Request Error?

The 404 Bad Request Error is classified under the 4xx HTTP status code mentioned above. This category of errors can be attributed to situations that are caused by the client and not the server itself. When these types of server errors occur, there should be a response generated explaining the error situation and whether or not it is considered temporary or permanent. 

The 404 Bad Request Error is a response from the server stating that the request could not be found. It indicates that the browser was able to communicate with the server, but the requested page that the client is trying to view could not be generated. This could be due to a broken or dead link within a webpage. Within a 404 error code, a more specific substatus code will be displayed, which further indicates the cause of the 404 error. Some examples of the substatus code include:

  • 404.0 – Not found
  • 404.1 – Site Not Found
  • 404.2 – ISAPI restricted
  • 404.3 – MIME restriction
  • 404.4 – No handler configured
  • 404.5 – Denied by request filtering configuration
  • 404.6 – Verb denied
  • 404.7 – File extension denied
  • 404.8 – Hidden namespace
  • 404.9 – File attribute hidden
  • 404.10 – Request header too long
  • 404.11 – Request contains double escape sequence
  • 404.12 – Request contains high-bit characters
  • 404.13 – Content length too large
  • 404.14 – Request URL too long
  • 404.15 – Query string too long
  • 404.16 – DAV request sent to the static file handler
  • 404.17 – Dynamic content mapped to the static file handler via a wildcard MIME mapping
  • 404.18 – Query string sequence denied
  • 404.19 – Denied by filtering rule
  • 404.20 – Too many URL segments

Why Do 404 Bad Request Errors Occur?

Some reasons that a 404 Bad Request Error might occur include:

  • Errors in a URL
  • Outdated DNS records
  • Not clearing a browser cache or cookies
  • File on web page is too large
  • Issue with hosting

How can a 404 Bad Request Error be Fixed?

With so many different types of 404 Bad Request Errors, it can be difficult for an organization to navigate what to fix and why it might have occurred. Luckily, a number of tools now exist that provide the ability to crawl a website and return pages that report a 404 status code so you have a better idea of where to begin. The only thing to consider is that these types of tools are only intended to crawl one particular website to discover any 404 errors. The other two types of ways to identify 404 Bad Request Errors are through Google Search Console and Google Analytics.

Google Search Console is a web service offered through Google intended for webmasters that allows them to check indexing statuses. This web service can assist with 404 Errors as it provides a list of links that received errors when crawling so they can easily be identified and fixed.

Google Analytics is more often used for reporting website traffic, but since it provides insight on metrics such as pages that attribute to bounce rate, it can help identify any pages where a 404 Error occurred, causing a visitor to leave a website. 

More often than not, hosting can also contribute to 404 Bad Request Errors. If the website uses shared hosting, it might be competing with too many other websites, resulting in poor performance and the inability to load a specific webpage. It is important that you choose a hosting service that can meet the needs of your website in terms of data storage to ensure it performs well and properly loads all pages on the clients end.

A better solution is to purchase dedicated hosting, which ensures better deliverability success for emails and less phishing activity because the server is not shared with thousands of other people. 

Need help with your website hosting?

Alliance Interactive is a top Washington, DC based website design and development agency with over 17 years of experience building and maintaining websites. We provide dedicated website hosting and maintenance solutions that can help in prevention of 404 Bad Request Errors and server issues. For more information about hosting plans and services please, Request More Details.