Status Code 400 – Bad Request

What is status code 400?

The server recognizes Status Code 400 or 400 Bad Request, or 400 error or HTTP error 400, as a general user error. If the server determines that the resulting error does not fall under any other status code classifications, it will throw the 400 bad error.

The 400 status code (Bad Request) indicates that the server was unable to process the request due to user error. In the event of a failed request, the server should return the specific 4xx status code in exchange for an invalid request.

Causes of Error 400:

1. URL String Syntax Error:

The most common cause of HTTP error 400 is an incorrectly typed URL (Uniform Resource Locator), deformed syntax, or a URL containing illegal characters.

Though the user may inadvertently type the incorrect URL, this can also occur if the URL encoding is incorrectly performed.

2. Corrupted Browser Cache and Cookies:

The server generates the 400 bad error code for reasons other than URL typos. Even if the URL is typed correctly, the server may still show a 400 Bad Request due to corrupted files in the browser cache or expired and damaged cookies.

If the user tries to access their WordPress admin area after some time has passed since their last login session, they may receive a 400 Bad Request error. The reason for this is that the process by which the cookie was managing the login authentication information may have expired, and it is now unable to authenticate the same valid user with admin rights.

3. DNS Lookup Cache:

The 400 Bad Request error message can occur if the local DNS data is out of sync with the registered DNS (Domain Name Server) data. All of the domain names available on the internet are works of art in the field of IP addresses. You can compare your phone number’s IP address as it connects to a specific “calling number” you want to dial.

4. File size too large:

A 400 Bad Request can also occur if the files uploaded by the user on a website are too large to meet the upload request. This is strictly related to the server’s file size limit and will vary depending on how it is configured.

5. Generic Server Error:

If there is a technical problem on the server side, the 400 bad request error may also occur. A 400 status code, on the other hand, indicates a general server problem, a server or network glitch, or any other undefined volatile issues.

Assume it occurs when the user attempts to connect to a third-party website, in which case the user has no control over it. At that point, he or she can try refreshing the browser and checking in at regular intervals to see if the website developers have resolved the issue. If you want to confirm whether the specific error is a server-side issue or not, try loading the website in different browsers, or test it on a different machine/device to rule out system-specific issues.

If the same problem occurs in other browsers, the system is confirmed to be a server-side issue. Also If the site’s content is important to you, you should contact the website’s owner directly and provide all relevant information about the operating system, browser, system, and versions you were using when you encountered the 400 bad error.

Fixing Error 400:

1. Check Submitted URL:

The obvious URL string itself is one of the most common causes of the 400 Bad Request error. By manually typing unwanted characters into the URL in the web browser, it is very easy to make mistakes.

Check the spelling of the domain name or the specific web page you want to access to ensure that it is correct and separated with forwarding slashes. If the URL contains any special characters, ensure that they are properly encoded with valid URL characters.

2. Clear Browser Cache:

If any website files stored locally are corrupted, the user receives a 400 Bad Request error when accessing specific website content.

It consists of all of the files that a website requires to function properly, as opposed to:

• PHP and HTML
• JavaScript
• Text and configuration files
• CSS coding Digital Media, as opposed to photos, videos, audio, and so on.
• XML, JSON, and other data files

When a user visits a website, all of the files listed above are saved locally on your computer’s browser. To resolve this issue, clear the cache memory of the browser.

3. Clear Browser Cookies:

If you still get the 400 error after clearing your browser cache, your browser cookies are probably corrupted. When you open a website in your browser, it uses a variety of cookies. If any of the used cookies expires or becomes corrupted, the 400 Bad Request error may occur.

4. File Upload Exceeds Server Limit:

When uploading a file, we frequently forget about the server size limit and exceed it. You eventually run into a 400 Bad Request error.
Try uploading a file again, but this time use a smaller file. If it uploads successfully, the error most likely occurred because the initial file was too large, and before uploading the file again, you must either trim the file size or find another way.

5. Clear DNS Cache:

If the DNS data stored locally becomes corrupted or out-of-date, the 400 Bad request will be issued.

6. Deactivate Browser Extensions:

Today, we install a variety of browser extensions. Some extensions may interfere with your website’s cookies, resulting in the 400 bad request error. To identify the true culprit, temporarily disable them and run the website again to see if it makes a difference.

Summary:

In this article, we covered the concept of the HTTP 400 error code. We covered the reasons that may cause this error code to appear. In the end, we also covered the solutions to these problems, to mitigate the problem of the 400 error code appearing.