How to Fix HTTP ‘400 Bad Request’ Error? [8 Methods]

What is a ‘400 Bad Request’ Error?

The “400 Bad Request” meaning is the server could not understand or unable to process a client’s request due to malformed or incorrect formatting.

When a server encounters this error, it means that the request sent by the client cannot be understood and the server cannot determine its status code category. This error arises from issues such as syntax errors, invalid data, or missing parameters.

What does 400 Bad Request Error look like on different Browsers?

You must have seen 400 Bad Request Errors many times on your Chrome browser, and it is a fact that, just like the 404 Not Found error, the 400 Bad Request error can also be customizable and may appear differently on different browsers.

If the website doesn’t have a custom error page, the browser will display the default error page. Let’s take a look at how it appears on different browsers.

400 Bad request Chrome

400 Bad request Chrome
400 Bad request Chrome

400 Bad request Firefox

400 Bad request Firefox
400 Bad request Firefox

400 Bad request Safari

400 Bad request Safari
400 Bad request Safari

400 Bad request Microsoft Edge

400 Bad request Microsoft Edge
400 Bad request Microsoft Edge

Why does 400 error occur?

There can be various reasons that cause 400 Bad request errors and even this error is not limited to only certain Browsers or Operating systems. Therefore, the troubleshooting method can be varied.

1. Incomplete URLs

A poorly constructed URL can trigger a “400 Bad Request” error. It can be due to a Typo error, using invalid characters, malformed syntax, or missing parameters, which can render the URL invalid, causing the server to reject the request.

2. Invalid or Missing Request headers

Request headers provide additional information about the client’s request. If the headers are invalid or missing, the server may not be able to process the request correctly, resulting in a “400 Bad Request” error.

3. Corrupt Browser Cache and Cookies

Even though the URL is correct, the 400 Bad Request error can be triggered due to corrupt files stored in the browser cache or issues caused by outdated cookies.

4. DNS lookup Cache

The 400 Bad Request error can also happen if the DNS cache gets corrupted. It refers to a situation where the information stored in the DNS cache becomes inaccurate, outdated, or inconsistent.

The DNS cache is responsible for storing previously resolved domain name-to-IP address mappings, allowing for faster and more efficient browsing by eliminating the need to query DNS servers repeatedly for the same information.

5. Large request size exceeding server limits

Servers often impose limitations on the size of files you can upload to prevent excessive resource consumption. When you attempt to upload a file to a website that exceeds the specified limit, the server cannot fulfill the upload request and rejects it, triggering a 404 Bad Request Error.

Read: 🚩 How to fix “the uploaded file exceeds the upload_max_filesize directive in php.ini” Error?

6. Invalid or unsupported HTTP methods

HTTP methods, such as GET, POST, or PUT, determine the type of request being made. If an unsupported or incorrectly specified HTTP method is used, the server cannot understand the request and responds with a “400 Bad Request” error.

7. Server Glitch

While the 400 Bad Request error is typically associated with client-side errors, it can also be triggered by server-side issues. This error indicates a general problem with the server, which could be caused by temporary server-related issues or minor glitches.

If this is the case, and you are trying to visit a third-party website experiencing the 400 Bad Request error due to server-side issues, you have limited control over the situation. The only options available to you are to refresh the website or periodically check its status to see if the web administrator has resolved the issue.

How to Fix A ‘400 Bad Request’ Error?

Now that you are aware of the most common causes behind 400 Bad Request errors, you might be wondering, “How can I fix a 400 Bad Request error?” or “What steps should I take to resolve it?”

Fortunately, the answer is straightforward and not as challenging as it may appear. Simply follow the steps outlined in this section to diagnose and resolve a 400 Bad Request error. The suggested solutions include the following:

Troubleshooting and Resolving “400 Bad Request” Errors: If you encounter a “400 Bad Request” error, follow these steps to troubleshoot and resolve the issue:

  • Verify the URL
  • Clear Browser cache and cookies
  • Temporarily Disable browser extensions or plugins
  • Update your browser to the latest version
  • Check for any required request headers or parameters
  • Split large requests into smaller ones or compress data
  • Clear DNS cache
  • Seek further assistance if the issue persists

Verify the URL

It is a very common problem as users often mistype the URL or domain name in a hurry. Therefore, it is crucial to check the spelling of the domain name, as well as any special characters or empty spaces in the URL, as they can potentially cause a ‘400 Bad Request’ error.

To resolve this issue, please verify the URL and carefully check for any typos or missing parameters. Ensure that the URL has the correct structure, contains all the necessary parameters, and does not include any invalid characters.

Clear Browser Cache and Cookies

Browser cookies and cache store data and content from websites on the client’s side, improving the browsing experience.

The browser cache holds website files like text and images, reducing the need to request them from the web server and making page loading faster. Meanwhile, cookies store the user’s session history and preferences, enabling personalized browsing.

However, cookies can expire over time, and both website cookies and cache can become corrupted, leading to a 400 bad request error.

How to fix 400 bad request error in Google Chrome?

To fix this, you need to clear the browser cache and cookies. If you are using Chrome browser, follow the steps given below:

Step 1: Depending on your browser, Go to the settings menu.

In Google Chrome, for example, you can find the settings menu by clicking on the three vertical dots located in the upper right corner of the window.

Step 2: To proceed, select “More tools” and then click on “Clear browsing data”.

Clear browsing data in Chrome
Clear browsing data on Chrome

Step 3: A pop-up window will be displayed, and you can choose all three options located under the “Basic” section as depicted in the picture below. These options consist of “Browsing history,” “Cookies and other site data,” and “Cached images and files.

Step 4: Click on “Clear data” to initiate the process.

Clearing data in Google Chrome
Clearing data in Google Chrome

Temporarily Disable browser extensions or plugins

Certain browser extensions or plugins can cause conflicts with the request sent to the web server, there is a possibility that the web server may consider the request as invalid or not properly formed.

Temporarily disabling them can help identify if any of these add-ons are triggering 400 Bad Request errors.

In the Chrome menu, click on Advanced Tools — Extensions. To disable them just uncheck the toggle on each of them. Make sure you disable all the extensions, it is very important to identify the reason.

Then, try to access the website again. If the error does not appear anymore, all you have to do is to find the extension causing the error. Turn on the installed extensions one by one and check the availability of the problem site after each one.

Update your browser to the latest version

Updating your browser can potentially help fix a 400 Bad Request error. When you update your browser, you ensure that it has the latest bug fixes, security patches, and compatibility improvements. These updates can address issues related to handling requests and processing data, which may help resolve the 400 Bad Request error.

Newer versions of browsers often include improvements in handling and validating HTTP requests, as well as enhanced support for web standards. By keeping your browser up to date, you increase the chances of encountering fewer errors and enjoying a smoother browsing experience.

To update Google Chrome browser, you can follow these step-by-step instructions:

  • Open Google Chrome on your computer.
  • Click on the three-dot menu icon located at the top right corner of the browser window.
  • From the drop-down menu, hover over the “Help” option.
  • In the Help submenu, click on “About Google Chrome.” This will open a new tab with information about your current Chrome version.
  • Chrome will automatically check for updates and display the update status. If an update is available, it will begin downloading and installing automatically.
  • Once the update process is complete, click on the “Relaunch” button to restart Chrome and apply the updates.
  • After Chrome relaunches, it should be updated to the latest version.

Note: The steps may vary slightly depending on the version of Chrome or the operating system you are using.

Check for any required request headers or parameters

You must ensure that all necessary information is included when making a request to a server. In certain cases, when interacting with a web server or an API, specific headers or parameters need to be provided to fulfill the requirements of the request.

Request headers are additional information sent along with the request to provide context or instructions to the server. These headers may include details such as the type of content expected, authentication credentials, or information about the client making the request.

Request parameters are data values that are sent as part of the request URL or in the request body. They provide specific information required for the server to process the request accurately. Parameters can include things like search queries, user IDs, or options for filtering data.

By checking for any required request headers or parameters, you ensure that all the necessary information is included and properly formatted in your request. This helps ensure that the server can process the request correctly and provide the expected response.

Split large requests into smaller ones or compress data

If you try to upload a larger file siize that exceeds server limit, then you will experiene a 400 Bad Request error.

There are a couple of things you can try. First, you can consider breaking down the request into smaller, more manageable pieces. By doing this, you’re giving the server a better chance to process each part without overwhelming it.

Another option is to compress the data before sending it. This can help reduce the overall size of the request, making it easier for the server to handle. Compression techniques can effectively shrink the data such as large audio files, videos or images without losing any important information.

Clear DNS cache

Another common reason you might encounter a 400 Bad Request error is when the local DNS lookup data on your computer becomes corrupted or outdated.

It’s important to note that the browser doesn’t handle this data directly; it’s actually stored by your operating system. But don’t worry, we’re here to help!

We’ve put together a comprehensive and detailed guide that will walk you through clearing the DNS cache for both Windows and macOS operating systems. This should help resolve the issue and get you back to a smooth browsing experience in no time.

Read: 🚩 How to Easily Flush DNS Command Cache (Windows, Mac, Linux)

Seek Further Assistance if the issue persists

If you’ve tried all the methods mentioned above, but unfortunately the error persists. That’s most probably due to the issue lies with a misconfiguration of the website itself. In this case, it’s a good idea to reach out to the website administrators and kindly report the error.

However, if you are a website owner, it is recommended to reach out to the support team of your hosting provider. They possess the expertise to resolve this issue and provide you with the necessary assistance to fix it.

How to prevent ‘400 Bad Request’ Error?

To minimize the occurrence of “400 Bad Request” errors, consider implementing the following preventive measures:

  • Double-check URLs and parameters: Before submitting a request, review the URL to ensure it is accurate and includes all the required parameters. This simple step can prevent potential errors.
  • Keep browsers and web applications up to date: Regularly update your browsers and web applications to their latest versions. This ensures compatibility with modern web standards and reduces the likelihood of encountering errors.
  • Validate user inputs on forms: When dealing with user input forms, implement proper validation to prevent the submission of invalid data. This validation can be done on the client-side using JavaScript or on the server-side to ensure data integrity.
  • Optimize website code and scripts: Regularly audit and optimize your website’s code and scripts to minimize the chances of syntax errors that could trigger a “400 Bad Request” error. Proper code organization and adherence to coding standards can help prevent such issues.
  • Implement proper error handling mechanisms: On the server-side, implement robust error handling mechanisms that provide meaningful error messages to users when a “400 Bad Request” error occurs. Clear and informative error messages help users understand the issue and take appropriate actions.
  • Regularly monitor server logs and error reports: Monitor your server logs and error reports to identify any recurring “400 Bad Request” errors. By proactively identifying and addressing these issues, you can prevent them from negatively impacting your website’s performance.


Understanding the “400 Bad Request” error is crucial for effectively taking steps to fix this issue. By identifying the common causes behind this error and following the troubleshooting steps discussed in this blog post, you can effectively resolve and prevent “400 Bad Request” errors.

Do not forget to check the URL, optimize your website’s code, and keep your browsers and web applications up to date. By implementing these best practices, you can enhance your website’s functionality and reduce the risk of encountering such errors in the future.
If you have any queries or suggestions regarding this post, please let us know in the comment section below.

Frequently Asked Questions

How do I fix a 400 Bad Request?

How to fix a 400 Bad request error? (8 methods)
1. Verify the URL
2. Clear Browser cache and cookies
3. Temporarily Disable browser extensions or plugins
4. Update your browser to the latest version
5. Check for any required request headers or parameters
6. Split large requests into smaller ones or compress data
7. Clear DNS cache
8. Seek further assistance if the issue persists

What is 400 Bad Request on Chrome?

A “400 Bad Request” error on Chrome is an HTTP status code that indicates the request sent to the server is invalid or malformed. This error occurs when the browser is unable to understand or process the request due to various reasons such as incorrect syntax, missing or incorrect parameters, or issues with the server configuration. I

What causes a 400 error?

The possible reasons that cause a 400 Bad gateway error are:
1. The causes of a 400 Bad request error are:
2. Incorrect URLs
3. Invalid or missing request headers
4. Corrupt Browser Cache and Cookies
5. DNS Lookup Cache
6. Large request size exceeding server limits
7. Invalid or unsupported HTTP methods
8. Server glitch

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