Web Browsers - How to Fix a "Bad Request" Error

Problem

When you attempt to access a website, you may sometimes instead receive a "Bad Request" error message where the website content should have loaded. This error often contains the number "400" and may include additional text, such as "Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit."

Solution

First, check the website URL you entered to make sure it is correct. If the web address appears to be entered correctly, then the issue can usually be resolved by clearing your browser's cache and cookies.

For instructions on performing these steps, click on the appropriate link for the web browser you are using:

Windows

Browser	Document Link
Internet Explorer 6	Internet Explorer 6 - Windows
Internet Explorer 7	Internet Explorer 7 - Windows
Internet Explorer 8	Internet Explorer 8 - Windows
Internet Explorer 9-11	Internet Explorer 9, 10, & 11 - Windows
Edge	Edge - Windows
Firefox 3.5	Firefox 3.5 - Windows
Firefox	Firefox - Windows
Chrome	Chrome - Windows
Opera	Opera - Windows
Safari	Safari - Windows

Mac OS X

Browser	Document Link
Firefox 3.5 - 20	Firefox 3.5 - 20 - Mac
Firefox 21+	Firefox 21+ - Mac
Chrome	Chrome - Mac
Opera 10.50	Opera 10.50 - Mac
Opera 28	Opera 28 - Mac
Safari 5	Safari 5 (and older) - Mac
Safari 5.1 - 7.9	Safari 5.1-7.9 - Mac
Safari 8.0+	Safari 8.0+ - Mac
Safari 10.0.1+	Safari 10.0.1+ - Mac

Mobile Operating Systems

Operating System	Document Link
Android	Android - Chrome
iOS	Safari - iOS
webOS	Web - webOS
Windows Phone	Internet Explorer - Windows Phone