Ошибка 400 request header or cookie too large

I am getting a 400 Bad Request request header or cookie too large from nginx with my Rails app. Restarting the browser fixes the issue. I am only storing a string id in my cookie so it should be tiny.

Where can I find the nginx error logs? I looked at nano /opt/nginx/logs/error.log, but it doesn’t have anything related.

I tried to set following and no luck:

location / {
    large_client_header_buffers  4 32k;
    proxy_buffer_size  32k;
}

nginx.conf

#user  nobody;
worker_processes  1;
#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;
#pid        logs/nginx.pid;
events {
  worker_connections  1024;
}
http {
passenger_root /home/app/.rvm/gems/ruby-1.9.3-p392/gems/passenger-3.0.19;
passenger_ruby /home/app/.rvm/wrappers/ruby-1.9.3-p392/ruby;
include       mime.types;
default_type  application/octet-stream;
sendfile        on;
keepalive_timeout  65;
client_max_body_size 20M;
server {
    listen       80;
    server_name  localhost;
    root /home/app/myapp/current/public;
    passenger_enabled on;
    #charset koi8-r;
    #access_log  logs/host.access.log  main;

# location / {
#   large_client_header_buffers  4 32k;
#   proxy_buffer_size  32k;
# }

     #  location / {
     #   root   html;
     #   index  index.html index.htm;
     #   client_max_body_size 4M;
#   client_body_buffer_size 128k;
# }
    #error_page  404              /404.html;

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   html;
    }

    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ .php$ {
    #    proxy_pass   http://127.0.0.1;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    #location ~ .php$ {
    #    root           html;
    #    fastcgi_pass   127.0.0.1:9000;
    #    fastcgi_index  index.php;
    #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
    #    include        fastcgi_params;
    #}

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /.ht {
    #    deny  all;
    #}
}


# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
#    listen       8000;
#    listen       somename:8080;
#    server_name  somename  alias  another.alias;

#    location / {
#        root   html;
#        index  index.html index.htm;
#    }
#}


# HTTPS server
#
#server {
#    listen       443;
#    server_name  localhost;

#    ssl                  on;
#    ssl_certificate      cert.pem;
#    ssl_certificate_key  cert.key;

#    ssl_session_timeout  5m;

#    ssl_protocols  SSLv2 SSLv3 TLSv1;
#    ssl_ciphers  HIGH:!aNULL:!MD5;
#    ssl_prefer_server_ciphers   on;

#    location / {
#        root   html;
#        index  index.html index.htm;
#    }
#}

}

Here’s my code storing the cookies and a screenshot of the cookies in Firebug. I used firebug to check stored session and I found New Relic and jQuery are storing cookies too; could this be why the cookie size is exceeded?

def current_company
  return if current_user.nil?
  session[:current_company_id] = current_user.companies.first.id if session[:current_company_id].blank?
    @current_company ||= Company.find(session[:current_company_id])
end

The 400 bad request error is an HTTP status code that describes an error caused by an invalid request. Thus, the server can’t understand and process it. Most HTTP error 400 bad requests are caused by malformed request syntax, invalid request message framing, or deceptive request routing.

If you’re browsing the internet and encounter this error, it’s possible to solve the problem easily. However, there are several occasions when the error comes from the website server. In this case, only the site owner can fix the problem.

This article will discuss eight methods of resolving a 400 bad request error. We will also cover the HTTP error 400 bad request message variations and their possible causes.

Variations of the 400 Bad Request Error

As an HTTP status code, the 400 bad request error informs users why they can’t access a web page. That said, the error message may vary or not show the error code itself.

Here are some variations of the 400 bad request error message you may encounter:

• HTTP Error 400
• HTTP Error 400 – Bad Request
• HTTP Error 400. The request hostname is invalid
• 400 Bad Request
• 400 – Bad Request. The request could not be understood by the server due to malformed syntax. The client should not repeat the request without modifications.
• 400 Bad Request – Request Header Or Cookie Too Large
• Bad Request – Invalid URL
• Bad Request – Error 400
• Bad Request – Your browser sent a request that this server could not understand

“400 Bad Request Error” on Different Browsers

Just like a 404 error page, the 400 bad request page is customizable. For example, Google has a custom 400 bad request error page that looks the same on all web browsers.

However, if the site doesn’t have a customized error page, the web browser will show the default one. Here is how the HTTP 400 bad request status code looks on different browsers:

Google Chrome

For 400 bad request, Chrome will show an error icon with The page isn’t working text followed by If the problem continues, contact the site owner. Then, you’ll find the HTTP ERROR 400 at the bottom of the message.

Microsoft Edge

Microsoft Edge has a design almost identical to Google Chrome’s, with the HTTP ERROR 400 text at the bottom.

Opera

The HTTP 400 bad request error in Opera displays the same text as Google Chrome. The only difference is the icon, as Opera uses its logo.

Mozilla Firefox

Mozilla Firefox will show a blank page when you try to access a website using the wrong syntax. There’s no text indicating that you encountered an HTTP 400 bad request error, which makes identifying the problem harder.

Safari

Like Mozilla Firefox, the browser will appear blank with no indication of the HTTP 400 bad request error.

Causes of the 400 Bad Request Error

When you try to access a website, your computer sends a request to the web server. Then, the server processes the request and sends back the page you want.

The error 400 bad request happens when the server can’t understand the request. Thus, it won’t process it and will send you the error code instead.

In most cases, client-side issues trigger the error. Some common causes of the 400 bad request error are:

• Malformed URL syntax – the URL may contain invalid characters such as {, }, [, or ]. A wrongly encoded URL can also contain wrongly used ASCII characters, such as double percentage characters.
• Large file size – websites have a file upload limit. An attempt to upload a file that exceeds this limit can be considered a bad request and trigger the HTTP 400 error status code.
• Corrupted browser cookies or cache – expired cookies or corrupted browser cache may interfere with the request and trigger the error. This commonly happens on login pages such as the WordPress login page.
• Bad DNS cache – if the website has moved to a new domain name or web host, the DNS cache data in your operating system may be invalid.

How to Fix a 400 Bad Request Error

The first action we recommend is refreshing the page. If that doesn’t work, then you should try the following methods.

1. Double Check the Domain Address

One of the most common causes of HTTP status 400 bad request error is a wrong URL. This may include a mistyped URL, malformed syntax, and illegal characters in the URL.

It’s easy to mistype a URL, so be sure to check the domain name spelling. If the URL contains a directory path, file name, or query string, pay attention to special symbols such as a hyphen (-) or percentage character (%).

For example, www.hostinger.com/tutorials is the correct domain name. If you type in www.hostinger.com/%tutorials in the URL bar with an extra percentage character, it will result in a 400 bad request error.

A badly encoded URL can also cause this error. URL encoding converts characters into ASCII characters to make them transferable on the internet. For example, one of the most common encodings is replacing space with %20.

However, a URL can be encoded incorrectly and thus contain incorrect syntax, like double percentage characters (%%). If you enter a URL or click on a link that’s badly encoded, you’ll end up with a bad request error 400.

When encountering a 400 bad request error because of a wrong URL, use an encoder/decoder tool. Decode the URL and encode it again to make sure it is correct.

2. Search the Keyword

There may be cases where you are sure that the URL is correct, yet the error persists. If you know the title of the article or page you’re looking for, search the keywords on the website or a search engine. Sometimes you can even see the title on the URL.

For example, in the /tutorials/how-to-make-a-website URL, you’ll see the article’s title at the end of the URL. If the website has a search feature, type the keyword to find the article.

Alternatively, use a search engine like Google or Bing. To perform a search on a specific site, type site: followed by the website’s URL and the keyword.

For example, the title of the article is how to make a website. Therefore, you type site:hostinger.com how to make a website.

3. Clear Browser Cache or Cookies

Browser cookies and cache store site data and content on the client’s side to improve the browsing experience.

The browser cache contains website files such as texts and images to reduce requests to the web server and make the page load faster. At the same time, cookies store the user’s session history and preferences to make personalized browsing possible.

However, cookies may expire after some time. Also, both the website cookies and cache can be corrupted and cause a 400 bad request error.

Additionally, HTTP status 400 bad request error can happen when the web browser sends cookie data that’s too large. In this case, the error message appears as 400 Bad Request – Request Header Or Cookie Too Large.

Try clearing your browser cache and cookies to solve this problem. If you’re using Google Chrome, here are the steps to do it:

1. Click on the three dots on the top right corner of Google Chrome and select Settings.

1. Find the Privacy and security section and click on Clear browsing data.

1. On the Clear browsing data window, check the Cached images and files and Cookies and other site data and use the drop-down menu to select the time frame.

1. Click Clear data and restart Google Chrome to finish the process.

Remember that clearing the browser cache and cookies resets the settings and signs you out of websites you’ve visited. Also, it will take more time to load the websites since the browser will need to retrieve the content previously stored in the cache.

If the cache and cookies were causing the 400 bad request error, you should be able to visit the website normally again. However, if it doesn’t work, try the next method.

4. Turn Off Browser Extensions

Browser extensions can also cause a bad request error 400. That’s because these extensions interfere with the request sent to the web server, which may lead the web server to interpret the request as invalid.

Moreover, browser extensions may affect cookies, which leads to a 400 bad request error. To find out if a browser extension is causing the problem, we recommend disabling all extensions first. Here are the steps for Google Chrome:

1. Click on the three dots on the top right corner of Google Chrome. Select More tools -> Extensions.

1. Turn off all extensions individually by clicking on the switch button.

1. Refresh the web page. If it loads normally, one of the extensions is causing the 400 bad request error.

After establishing that one of the extensions triggered the error, you need to identify the exact extension. Turn on the extensions one by one, refreshing the web page each time.

If you encounter a 400 bad request error after turning on one of the extensions, you’ve found the one causing the error. Keep the extension disabled or remove it altogether by clicking the Remove button on the extension settings page.

5. Check the File Size

Trying to upload a file that exceeds the server file size limit might trigger an HTTP status 400 bad request error. Sites usually have a different file upload limit, so check if the file you want to upload fits the limit.

If the website doesn’t mention the file limit, upload a small file to check whether that’s causing the error. If it works, then you should resize the file you originally wanted to upload.

Keep in mind that file compression may negatively affect its quality. If it’s a PDF or image, it can make the content blurry and unreadable. Be sure to check the quality of the file after compression and make sure that it’s still acceptable.

There are many free online compression tools so that you don’t need to install additional software on your computer. Some of the great examples are HiPDF for PDF files and UniConverter for video and audio files.

6. Flush DNS Cache

When you visit a site for the first time, the system goes through a DNS lookup, which searches for the nameservers and IP addresses that are associated with the domain name.

Your operating system then stores the IP addresses of the web servers in the DNS cache. Therefore, the system can reduce the DNS lookup process on the next visit, making the site load faster.

However, a corrupted or outdated DNS cache can trigger the HTTP error 400 bad request. In this case, you need to flush the DNS cache.

Since the DNS cache is stored in the operating system, the methods to flush it may vary. If you use Google Chrome, you’ll also have to flush the DNS cache in the web browser.

Here are the steps to do it on Windows and Mac OS:

Microsoft Windows 10

1. Right-click on the Windows Start Menu and select Search or use the search box in the taskbar if enabled.

1. Type command prompt and select the Command Prompt application.

1. Type ipconfig /flushdns and press Enter.

1. You’ll see the Successfully flushed the DNS Resolver Cache message after the process is completed.

macOS X

Press the F4 key to open Launchpad and enter Terminal to open the command terminal. Run the following command if you use macOS Sierra, X El Capitan, X Mavericks, X Mountain Lion, or X Lion:

sudo killall -HUP mDNSResponder.

Google Chrome

1. Type chrome://net-internals/#dns on Google Chrome’s address bar and press Enter:
2. Click Clear host cache.

If you use a different operating system, make sure to check our comprehensive guide on how to flush DNS cache.

7. Contact the Site Owner to Report the Error

If all attempts to fix the 400 bad request error didn’t work, there’s a possibility that the problem isn’t a client error but rather is a misconfiguration that the web owner needs to fix.

In this case, try to visit the contact page of the website and fill a contact us form, if available. Otherwise, most sites also have contact email addresses and social network accounts where you can inform them about the 400 bad request error.

8. Restart Your PC and Other Hardware

The last method is to restart your computer and network connection hardware, such as router and modems.

Restarting a PC often solves various problems, including the 400 bad request error because it clears the Random Access Memory (RAM). Moreover, it flushes the temporary cache that’s created as you open and close programs.

Temporary data from background processes may interfere with the request sent to the server, causing the 400 bad request error.

Conclusion

The HTTP status 400 – bad request indicates that the request sent to the server is invalid or corrupted. Just like other 4xx status codes, a 400 bad request is a client-side issue.

It can be caused by malformed request syntax, invalid request message framing, or deceptive request routing.

Since this is a client-side problem, users can easily resolve most of the 400 bad request errors. To recap, here are eight methods to resolve the error:

1. Double-check the domain address.
2. Search the keyword.
3. Clear browser cache and cookies.
4. Turn off browser extensions.
5. Check and reduce the file size.
6. Flush the operating system’s DNS cache.
7. Report the error to the site owner.
8. Restart the PC and networking equipment such as the router and modem.

If you have other tips or solutions, feel free to leave us a comment below.

We open many websites at one time on our browser to search for something on the internet. There are some websites that we check daily; it can be a news site, your work login, or something else. If such important websites show errors like ‘400 Bad Request, Request Header or Cookie Too Large,’ it can get frustrating.

At times, you will see the same error on all the different browsers available on your computer for a specific website only. Let’s get started on what this error is and how to eliminate it to enjoy browsing again.

The ‘request header too large’ error message can be seen on any website for two main reasons. One reason is that the size of the cookie for that particular domain is too large, and therefore the server refuses to display the website. Another reason for the ‘400 Bad Request, Request Header or Cookie Too Large’ error message is corrupted cookies.

Well, you can experience this error on Google Chrome, Microsoft Edge, Mozilla Firefox, or any other browser. This error happens mostly on the sites that are running on the Nginx server.

How To Fix Request Header Or Cookie Too Large Error

You can clear cookies and cache for that particular website to fix this 400 bad request error on your browser.

Note: The solutions are suggested with regard to different famous browsers. You can jump to the web browser section you are currently using and understand how to fix request header or cookie too large.

Google Chrome

There are two ways to reach the cookie settings. You can open the new tab in the browser and type –

chrome://settings/cookies 

If you don’t want to go the direct way, follow steps 1 to 3 below. You need to follow instructions from step 4, irrespective of what way you choose to reach the cookie settings page.  

Step 1: Open Google Chrome browser and click on the 3 dots in the upper right corner of the browser window. Select Settings from the menu.

Step 2: In the Settings tab, scroll down to Privacy and security and click on the arrow next to Site Settings.

Step 3: Now, click on Cookies and site data under the Content section.

Step 4: Click on the arrow next to See all cookies and site data on the next screen.

Step 5: You can either delete all the cookies by clicking on the Remove All option or delete the cookie of the affected website by clicking on the delete icon next to it.

If you don’t find the problematic web page easily, you can search for it in the search bar.

Once the cookies are deleted, you can relaunch the browser. In the browser, check if you can access the website giving ‘400 Bad Request, Request Header or Cookie Too Large’ errors or not.

Microsoft Edge

Microsoft Edge does not allow you to clear cookies for a single website. You need to clear cookies and site data for all the websites. There is a timestamp option available which allows you to remove browser cookies for a specific time frame.

Open the Microsoft Edge browser and click on the 3 dots in the top right corner of the browser. Click on the Settings from the menu.

In the Settings tab, click on Privacy, search, and services from the left tab.

Next, scroll down to the Clear browsing data section and click on the Choose what to clear button.

Select the Time range; if you wish to avoid deleting all cookies, select the Last hour option. Also, check the checkbox next to Cookies and other site data.

Click on the Clear now button.

Close the Microsoft Edge browser and open it again. Once opened, try accessing the website that was giving an error. If corrupted cookies were a problem, you would be able to access the website again on the browser without a request header or cookie too large error message.

Mozilla Firefox

If you are Mozilla Firefox, you can get rid of cookies from a problematic website easily.

Step 1: Open the Mozilla Firefox browser on your computer and click on 3 lines in the upper right corner. Select Settings from the menu.

Step 2: From the Settings tab, click on Privacy & Security.

Step 3: Now, scroll down to Cookies and Site Data and click on the Manage Data option.

Step 4: In Manage Cookies and Site Data window, select the website that was giving 400 Bad Request, Request Header or Cookie Too Large error, and click on Remove Selected.

Make sure you don’t click on Remove All; it will remove cookies and cache from all websites you have browsed.

Opera Browser

If you are a fan of Opera browser, you would like to know how to get rid of the Request Header or Cookie Too Large error in Opera.

Launch the Opera browser and Easy setup option (3 lines) in the top right corner. Click on Go to full browser settings seen at the end of the menu.

Next, expand the Advanced section and click on Privacy & security.

Now, open the Site Settings

In the Site Settings, click on the arrow next to the Cookies and site data under Content.

Scroll down and click on See all cookies and site data

Click on the delete icon next to the website that was showing the 400 Bad Request error. You can search for that website in the search box if you don’t find it easily.

You can relaunch the browser and try opening the website again.

Internet Explorer

Although Internet Explorer is not used much nowadays, some people rely on it for work purposes. Know how to clear cookies and get rid of the 400 Bad Request, Request Header or Cookie Too Large error message.

Open Internet Explorer and click on the Settings gear in the top right corner of the browser. Select Internet options from the Settings menu.

In the Internet options dialog box, click on the General tab and then click on the Settings button under Browsing history.

Now, under the Temporary Internet Files tab, click on the View files button.

The File Explorer window will open, and you will see files with the website name. You can delete the file that has the affected website name. Make sure you press the Shift + Delete keys to delete that file from your computer permanently.

Now, relaunch the Internet Explorer and browse the website that was giving errors before.

Use Third-party Application

Some people use multiple browsers to keep their work and entertainment tabs separated. Well, in such a case, deleting cookies from each of the browsers can be tedious work. You need to launch and relaunch all the browsers just to clear cookies for one particular website.

For such a user, we recommend using a third party tool called CookieSpy. It is a free tool that allows you to view and delete cookies from multiple browsers in one window. The currently supported browsers are Google Chrome, Mozilla Firefox, Apple Safari, Internet Explorer,  and Opera.

CookieSpy can be used only to view and delete cookies. It does not support any other feature than that. This makes it convenient for people who want an app just to clear cookies from different browsers.

When you install CookieSpy, it will detect all the browsers on your computer and have tabs for all the different browsers showing saved cookies. You can delete cookies for any site on any browser from the CookieSpy window.  

Download CookieSpy

Conclusion

The 400 error can be seen anywhere while you use the browser. It can get extremely annoying when you are not able to access important work-related websites. The website itself can resolve the 400 Bad Request, Request Header or Cookie Too Large error message in a few minutes if the error is from their end because of cookie size.

However, if the error is because of corrupt cookies in your browser, the only way to fix the 400 Bad Request error message is to clear cookies for that website. You can easily clear cookies from Google Chrome, Microsoft Edge, Mozilla Firefox, and Opera Browser. But when it comes to Internet Explorer, you need to delete it via File Explorer.

The process of clearing cookies for Internet Explorer via File Explorer is mentioned above, but we recommend switching from Internet Explorer to a different browser, as Microsoft is ending support for Internet Explorer from August 2021.