HTTP Error 400 The size of the request headers is too long SharePoint Online Office 365

In this SharePoint Online tutorial, we will discuss how to resolve Bad Request – Request Too Long. HTTP Error 400 The size of the request headers is too long error which comes in SharePoint Online Office 365.

Recently while opening a SharePoint online Office 365 site in Google Chrome, it shows the below error.

Bad Request – Request Too Long
HTTP Error 400 The size of the request headers is too long

You can see the error screenshot.

HTTP Error 400 The size of the request headers is too long SharePoint
HTTP Error 400 The size of the request headers is too long SharePoint

HTTP Error 400 The size of the request headers is too long SharePoint Online Office 365

The solution that worked for me is to delete the Google Chrome browser cache. I was getting the issue of Google Chrome.

Open Google chrome settings. Then expand the Settings menu. Then expand Advanced like below:

http error 400. the size of the request headers is too long. office 365
http error 400. the size of the request headers is too long. office 365

There click on Privacy and security. In the Privacy and security section click on “Clear browsing data”.

he size of the request headers is too long SharePoint
The size of the request headers is too long SharePoint

Then you can select Time range “All time” and then click on “CLEAR DATA” like below:

http error 400. the size of the request headers is too long. sharepoint
http error 400. the size of the request headers is too long. sharepoint

Now open the SharePoint online URL, you will not get the error “HTTP Error 400 The size of the request headers is too long”.

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Hope this SharePoint tutorial, helps to solve Bad Request – Request Too Long. HTTP Error 400 The size of the request headers is too long which comes in Google chrome while opening the SharePoint Online Office 365 site.

  • Hey Bhavana, thanks for sharing this. For our users, this is a recurring issue on a Sharepoint application. Asking the users to delete the cookies every time is not a solution that can work in the long run. Is there an alternate/permanent fix? Appreciate your help!

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