At times, when you visit a website you may get to see a 400 Bad Request message. The first thing you should try is to hard refresh the web page by pressing Ctrl+F5. If it does not help, there is something else that yo can do. But before that let us try and understand why this happens.
When you go to visit a web page, if the server finds that the size of the Cookie for that domain is too large or that some Cookie is corrupted, it will refuse to serve you the web page. Instead, in you browser window, it will show you 400 Bad Request, Request Header or Cookie Too Large or Big error. This is typical for nginx servers.
400 Bad Request
If you receive this error frequently, the best thing to do is to delete the Cookies for that particular domain. Let us say, if you are receiving this error when you visit any page on say, example.com, then you should delete all the Cookies of example.com from your browser’s cache.
While you can always use a tool like CCleaner to empty your entire cache, if you don’t want to do this, you will have to clear the Cookie for that particular domain only.
These posts will show you how to do it:
As I mentioned earlier – If you do not wish to do this, you can also clear the entire Cookie cache of that browser, via its settings or options. Note that, when you exercise this option, you will be deleting all your Cookies and therefore your settings as well as your logins.