When going to any Internet page, the user may be faced with the inability to open this page and the corresponding messages “400 Bad request” and . The latter usually indicates the presence of syntax errors in the user's Internet link, as well as possible problems in the operation of the provider and the user's PC. In this article I will tell you what 400 Bad request means, what are the causes of this dysfunction, and will share instructions for fixing it.

Translated from English, the text of this message sounds like "400 bad request", and usually indicates a situation in which the user used incorrect syntax when accessing some network resource.

Simply put, a user request that was sent to some server (often a trivial request to load an Internet page) was incorrect or corrupted, and the server was unable to recognize it.

The reasons for the appearance of 400 Bad request may be the following:

After we have figured out what 400 bad request means, we need to start eliminating it.

How to fix 400 Bad Request error

To get rid of 400 Bad Request do the following:

• Carefully check the Internet link you are using for errors (extra or missing characters, spaces, unused characters like %, etc.). Enter the correct link and repeat the request;

  

• Clear your browser's cache and cookies. For example, in Mozilla this is done by going to “Settings” - “Privacy”, and deleting the history after closing the browser (cache and cookies will be deleted). Since many sites throw a 400 error when their cookies are corrupted or out of date, clearing your cookies will help resolve the 400 Bad request error;
• Clear the DNS cache. To do this, open a command prompt as an administrator, enter: ipconfig /flushdns and press enter;
• Temporarily disable your antivirus and firewall. The latter can block access to the desired site, and their temporary deactivation will help in solving the problem of error 400;
• And . Tools such as “Dr.Web CureIt!”, “Trojan Remover”, “AdwCleaner” and other analogues will help;

  

• If you receive a 400 error while uploading a file to the server, it may mean that the file is too large and the server is not accepting it;
• If the 400 error happens on almost every site, then it is quite possible that there are problems with your ISP, or with your Internet connection. Check the speed of your Internet (network speed tests at the “Speedtest.net” level will help), and also check with your provider if they are carrying out any technical work;

  

• Try accessing the desired site directly (that is, for example, instead of otvet.mail.ru/?fr=mailrufm=2, contact www.mail.ru directly). Perhaps the site is experiencing problems with a specific page, and it would be a good idea to report them to the resource administration;
• Just wait. There may be technical problems with the site, which will be resolved soon.

What is this 400 Bad Request Request Header Or Cookie Too Large nginx?

Also, a number of users may encounter the error “400 Bad Request Request Header Or Cookie Too Large nginx,” which usually occurs when watching videos on any network resources.

As indicated in the text of the error itself, this problem is usually associated with damaged cookies on the user's computer. To solve it, you just need to go to your browser settings, clear the cache and cookies, and then restart the browser itself. After this, the problem is usually resolved.

Conclusion

We looked at what a 400 Bad request is, what are the reasons for this dysfunction, and how to fix it. In most cases, the factor causing this problem is the incorrect text of the link entered by the user in the address bar of the browser. The solution to the problem is to follow the tips I have listed; they will help fix the 400 Bad request error on your PC.

Internet surfers very often encounter the problem that instead of the intended page, when opening a resource in a web browser, a 400 error containing a description of the incorrect request is displayed. It is believed that this failure is classified as a user failure, and is associated with errors in entering the address of the requested resource, but this is not always the case.

Error 400 (Bad Request) - what is it?

Initially, the error itself can be interpreted precisely as an incorrect request, when an Internet surfer enters an incorrect resource address. This is a so-called syntax error. For example, when trying to access the Mail.Ru mail server, a Ukrainian user can easily enter the domain UA instead of RU, rightly believing that initially the site can redirect depending on the region or location of the user.

But such a domain actually does not exist. So it turns out that instead of entering the start page, the surfer receives a message that a 400 error has occurred (Bad Request - incorrect, incorrect or bad request).

Impact of Windows Services

One of the reasons for the failure, as some experts note, may even be the influence of the services provided by anti-virus software and the security systems of the Windows operating system itself.

The same firewall (firewall) or Windows Defender can easily provoke a situation where error 400 appears. In this case, we are talking about blocking sites and their content. To eliminate this problem, in the simplest case, you should add the address of the Internet resource to the list of exceptions of all security programs. In the case of a built-in firewall, you will have to create a new rule.

Error Code 400: Nginx

Often the appearance of an error message is accompanied by an indication of blocking by the Nginx service. There can be two situations: either it is a virus, or the original component actually worked, which, however, is used exclusively in UNIX-like systems, and by and large should have nothing to do with Windows.

The trouble is that in this case a request is made to the server, which is running such an OS, which can block requests made from a specific IP address. In turn, the address itself is marked as unreliable and entered into a special firewall LOG file, which should prevent further attempts to access it. The message that a 400 error has occurred may directly indicate that the system contains a huge amount of computer garbage in the form of caches and Cookies. All this needs to be cleaned.

What to do first?

In all cases when error 400 occurs, first in the browser or using system tools (if by default the Internet is accessed through built-in tools like Internet Explorer or Edge), clear your browsing history, delete cache and cookies. By the way, you can use exclusion lists only after complete cleaning.

Doing this manually is a thankless task, so to simplify the work you should give preference to automatic optimizer programs (Glary Utilities, Advanced System Care, CCleaner, etc.).

On the other hand, it is worth checking the system for various types of adware or spyware, using not an anti-virus scanner, but portable versions of applications like Anti-Malware.

Sometimes even a simple computer restart can help. It is possible that this error was caused by a short-term glitch in the operating system or the default browser (it is very possible that when accessing the requested page in another browser, the error will not appear). In general, the bulk of the work to fix the problem comes down to freeing up system resources and browser memory. After this, the problem disappears in almost all cases, except for the lack of connection or low Internet connection speed, when a timeout may occur - the server waits for a response to a request. But this is another question, although the solutions proposed for this situation also help in other cases when the problem is related to requests in browsers.

For those who do not want to deal with the problem on their own, a special Fix It utility from Microsoft has been created, which can correct some Internet connection errors (and not only). So you shouldn’t neglect such a tool either. In some cases, it can be an effective means of eliminating failures of this kind.

Error 400 Bad Request Nginx is quite rare. It means that the request to the server was formed incorrectly and is therefore rejected. This can be caused by various reasons. For example, one of the HTTP headers has been changed, and the checksum fields have not been corrected, and so on.

In this article we will look at a special case of this error - Request header or cookie too large Nginx. Let's look at what causes this error, why it might occur, and how to fix it.

What does Request header or cookie too large mean Nginx

The Request header or cookie too large error means that the request that was sent to the web server is too large. The request is usually divided into two parts: the header - where the general information is located, and the body of the request. Typically the request body should be large and its large size does not cause any problems. Whereas the header is usually not large, and if the browser does something wrong and transfers too much data, you will get such an error.

There are two options to solve the problem:

• Correct the site code- naturally, the browser itself will not issue you such requests. They are the result of an error in the site code, which means that by correcting the code, you will solve the problem;
• Increase maximum header size- if you are sure that the header should be large and this is normal for your site, then perhaps you should increase the header size limits in Nginx;
• If you are a user, then wait until the resource administrator corrects the error.

How to fix Request header or cookie too large Nginx

The maximum size of the transmitted packet is determined by three parameters that must be placed in the http section:

• client_body_buffer_size- buffer size for the request body;
• client_header_buffer_size- header buffer size;
• large_client_header_buffers- the maximum number and size of a buffer for reading a large header.

We're most interested in the last line. The first parameter is the number of buffers, and the second is the size of each of them. If the header size exceeds the size of one buffer, the user will receive a 414 error. By default, the size of one buffer is 8 kilobytes. We set the buffer size for regular requests to 8 kilobytes:

client_header_buffer_size 8k;

Then we create eight buffers with a size of 64 kilobytes to store large headers. Buffers are allocated as needed, so you don’t have to worry too much about memory consumption:

large_client_header_buffers 8 64k;

These lines need to be added to the http section before all server sections. Then you can restart Nginx:

And check if the error is reproduced. If everything was done correctly, then there should be no more errors.

conclusions

In this short article we looked at what to do with the request header or cookie too large nginx error. If you have access to the server on which the site is located via ssh, then you can fix it in a few minutes. If you have any questions, ask in the comments!

Related posts:

Error 400 bad request nginx means that an invalid request was made. If we are talking about requests to a database or API, the reason may be in the work of the backend. For example, there is not enough characters in the database field.

If an error occurs when accessing the main page of the site, the reason is usually Nginx and buffer sizes.

Error 400 bad request nginx

The amount of headers in a request may vary. If it is large and the limit set in the configuration does not allow them to be processed, an error will occur.

The error can be corrected by adding the following directive to the http section of the nginx.conf configuration file:

large_client_header_buffers 2 12k;

Then the web server is restarted

Usually receiving 400 bad request nginx in the browser is enough to eliminate the causes. However, you can additionally check the Nginx logs

less /var/log/nginx/error.log

If the error occurs periodically, you can find it in the access log using grep all cases of receiving a 400 response, then compare the data with entries in error.log.

Access.log will contain queries that were executed when accessing the site.

There are also others that are worth paying attention to. Especially if the server serves a loaded project.

When going to any site, or selecting any of the subsections of the site, the user may encounter the message “Request Header Or Cookie Too Large”, and further navigation through the selected link becomes impossible. This is usually due to damaged cookies for this site on the user’s PC, but it is also possible that the problem is caused by incorrect settings for this resource set by the webmaster.

Error with message text

The problem we described earlier may also occur.

What is this error “Request Header Or Cookie Too Large” and its causes

The translation of “Request Header Or Cookie Too Large” is “The request header or cookies are too large.” Typically this refers to a situation where, when a browser requests access to a resource, the server detects that the resource's cookies stored on the user's PC are too large or corrupted. The server refuses to process the request, which is accompanied by the message “400 bad request”, as well as the message I mentioned “Request Header Or Cookie Too Large”.

This error is typical for nginx servers (i.e. servers running on Unix-like operating systems) . Once it appears, access to the requested site (or its subsection) becomes impossible, and reloading the problematic page via Ctrl+F5 usually does nothing.

In addition to damaged cookies, the following determinants may be the cause of this dysfunction:

How to fix 400 Bad Request

When trying to get rid of a problem that has arisen, it is important to consider that the problem may be with you (if you are an ordinary user) or with the resource itself. Therefore, if you have used all the user tips below, and nothing has helped, then it may be worth contacting the resource’s technical support (or directly to the webmaster) and describing the problem that has arisen.

To resolve the "Cookie Too Large" problem, do the following:

This is implemented by the following entry:

Conclusion

The solution to this Request Header Or Cookie Too Large problem on the user’s part is to delete the cookies of the problematic site on the user’s computer. And on the part of the resource administration, an effective way to solve the problem would be to change the “large_client_header_buffers” parameter in nginx. In most cases, implementing these tips helps to get rid of the error that has arisen, resuming full work with the site on your PC.

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