How To Fix “Request Header or Cookie Too Large” Issue

Web users and developers alike occasionally come across the notorious “Request Header or Cookie Too Large” error. While it may initially seem perplexing, understanding this issue and knowing how to fix it is simpler than you think.

This guide aims to elucidate the causes behind this common HTTP status error and provides comprehensive step-by-step solutions to rectify it.

Causes of the Request Header or Cookie Too Large Error

The “Request Header or Cookie Too Large” error, also known as HTTP 400 Bad Request error, usually surfaces when the size of the HTTP header or the cookie in the user’s web browser exceeds the server’s limit.

This limit is typically configured to prevent any potential denial of service (DoS) attacks but can sometimes impede regular browsing sessions.

Two main causes trigger this error:

Excessively Large HTTP Headers: HTTP headers contain information about the request or response, or about the object sent in the message body. When these headers are filled with excessive data, it can exceed the server’s buffer size, leading to this error.

Oversized Cookies: Websites use cookies to store small pieces of information in the user’s web browser. If a website stores a large amount of data in cookies, the combined size of the cookies could breach the server’s limit.

Solutions to Fix the Request Header or Cookie Too Large Error

Depending on the root cause, there are different ways to fix the “Request Header or Cookie Too Large” error:

Solution 1: Clearing Browser Cookies

This is often the quickest and simplest way to resolve the “Request Header or Cookie Too Large” error. Here’s how to do it on different browsers:

Google Chrome:

1. 1. Click on the three-dot icon located at the top-right corner of the browser.
   2. From the dropdown menu, click on ‘Settings’.
   3. Scroll down and click on ‘Privacy and Security’.
   4. Click on ‘Clear Browsing Data’.
   5. A pop-up box will appear. Check the ‘Cookies and other site data’ box and click on ‘Clear Data’.

Mozilla Firefox

1. 1. 1. Click on the menu icon (three horizontal lines) at the top-right corner.
      2. From the dropdown menu, click on ‘Options’.
      3. Click on ‘Privacy & Security’ from the menu on the left.
      4. Under ‘Cookies and Site Data’, click on ‘Clear Data’.
      5. Uncheck ‘Cached Web Content’ and then click ‘Clear’.

Safari

1. 1. Go to ‘Safari’ in the menu bar.
   2. Click on ‘Preferences’.
   3. In the ‘Preferences’ window, click on ‘Privacy’.
   4. Click on ‘Manage Website Data’ and then ‘Remove All’.

Solution 2: Using a Different Web Browser

If the first solution doesn’t work, try using a different web browser. Here’s how to do it:

1. Install a different web browser if you don’t already have one. There are various options like Google Chrome, Mozilla Firefox, Safari, Microsoft Edge, etc.
2. After installation, open the browser and type in the URL of the site you were trying to visit.
3. Check to see if the error persists.

Solution 3: Reducing the HTTP Header Size

This is more applicable for website owners or developers. Here’s how to reduce HTTP header size:

1. Identify the elements of your HTTP headers that are contributing most to its size. This could be cookies, user-agent, referrer, etc.
2. Limit the number of cookies used by your website. Also, reduce the amount of data stored in each cookie.
3. Implement header compression techniques where applicable. For instance, consider HTTP/2, which allows header field compression.

Solution 4: Increasing the Server Limit

This is another solution more applicable for website owners or administrators. The steps to increase the server limit depend on your server’s specific software. Generally, it involves adjusting the configuration to allow larger headers or cookies.

Remember to consider potential security concerns when doing so, as larger header sizes can make your server more susceptible to DoS attacks.

In Apache, you can do this by editing the ‘LimitRequestFieldSize’ directive in your server configuration. In Nginx, you would adjust the ‘large_client_header_buffers’ directive. Always consult the documentation of your specific server software for detailed instructions.

Conclusion

The “Request Header or Cookie Too Large” error is a common yet fixable issue. Whether you’re a site user encountering this error or a website owner trying to deliver a seamless browsing experience, understanding the causes and applying the above step-by-step solutions can help navigate this problem.

By regularly maintaining the size of your HTTP headers and cookies, you can ensure optimal website performance, thus improving your overall user experience. With adequate knowledge and appropriate actions, such HTTP errors won’t stand a chance!