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

This SharePoint Online tutorial explains how to fix HTTP Error 400. The size of the request headers is too long.

This error typically occurs when your web browser sends too much data in the request header, which SharePoint Online cannot process.

Also, we will see how to solve http error 400 for MS Excel and MS Word.

Http Error 400. The size of the request headers is too long. SharePoint Online [Solved]

Here, I will give you two solutions. Now let’s talk about the first solution:

Sometimes, the browser cache can become corrupted, leading to larger-than-normal request headers. Clearing them can often resolve the issue. Follow the below steps to Clear the Browser Cache.

1. Open your browser in which you get the error, click the three dots, then click ‘Clear browsing data…‘

2. Then click on Clear Data to clear Google Chrome cache.

The second solution is to use another browser or use an incognito window to pass requests in the browser.

Http error 400. the size of the request headers is too long. Excel

If you encounter the HTTP Error 400 ‘The size of the request headers is too long’ in Excel, I will now explain how to resolve it.

1. Open the MS Excel application, then click the Options.

2. Then, under the General option, click Privacy Setting…

3. uncheck the Turn on experiences that download online content. Then click OK.

This way, you can solve http error 400 in Excel.

Http error 400. The size of the request headers is too long. Word

When I try to add a custom watermark into Word, it gives Http error 400. The size of the request headers is too long error.

To solve this error, you can follow the above steps that I tell you in the Http error 400. The size of the request headers is too long. The only difference is the time we open Excel. Now you open MS Word. The other steps are the same.

By following these steps, you can solve http error 400 for MS Word.

I hope this article solves your problem. In this tutorial, we learned how to fix the HTTP Error 400: ‘The size of the request headers is too long’ in SharePoint Online, Excel, and Word.

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