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

This document describes what to do if you receive a 400 Bad Request error message upon loading a website.


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."


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:

Desktop Web Browsers

Note: Clearing browser cache prevents you from using old/out-of-date versions of websites and protects your personal information. It also helps running some applications better on your computer by freeing up space.

BrowserWindows Document LinkmacOS Document Link
Google Chrome
Google Chrome
Chrome (Win) - Clearing Cache and CookiesChrome (Mac) - Clearing Cache and Cookies
Firefox 57+ (Win) - Clearing Cache and CookiesFirefox 21+ (Mac) - Clearing Cache and Cookies
Safari (Win) - Clearing Cache and CookiesSafari 10.0.1+ (Mac) - Clearing Cache and Cookies
Internet Explorer 9, 10, & 11
Internet Explorer 9, 10, & 11
Internet Explorer 9, 10 and 11 (Win) - Clearing Cache and CookiesNone
Microsoft Edge
Microsoft Edge
Edge (Win) - Clearing Cache and CookiesNone
Opera (Win) - Clearing Cache and CookiesOpera 28.0 (Mac) - Clearing Cache and Cookies
New Microsoft Edge
New Edge (Win 10, 8, 7, MacOS) - Clearing Cache and CookiesNew Edge (Win 10, 8, 7, MacOS) - Clearing Cache and Cookies

Mobile Web Browsers

Operating SystemDocument Link
Android Icon
Android (Jellybean) - Clearing Cache and Cookies on Google Chrome
iOS Icon
iOS - Clearing Cache and Cookies
webOS Icon
HP webOS 2.x - Clearing Cache and Cookies
Windows Phone Icon
Windows Phone
Internet Explorer (Windows Phone) - Clearing Cache and Cookies

Legacy Versions

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