We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

400 Bad Request Request Header Or Cookie Too Large nginx - What does this error mean?

  • 5 replies
  • 148 have this problem
  • 1 view
  • Last reply by cor-el

more options

On CNN.com i get this error when trying to view video or when clicking on one of their tabs:

400 Bad Request Request Header Or Cookie Too Large nginx

On CNN.com i get this error when trying to view video or when clicking on one of their tabs: 400 Bad Request Request Header Or Cookie Too Large nginx

Chosen solution

That issue can be caused by corrupted cookies.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

  • Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

  • Tools > Options > Privacy > Cookies: "Show Cookies"

See also:

Read this answer in context 👍 22

All Replies (5)

more options

Chosen Solution

That issue can be caused by corrupted cookies.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

  • Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

  • Tools > Options > Privacy > Cookies: "Show Cookies"

See also:

more options

Worked perfectly! Thanks, cor-el

more options

Thank you very much cor-el. You just save me lots of time looking for the problem myself or deleting FF completely...

more options

Under Tools, Firefox has no entry called "Options"...so this solution doesn't work...

more options

Instead of Tools > Options use:

  • Mac: Firefox > Preferences
  • Linux: Edit > Preferences
  • Windows: Firefox > Options

Press F10 if the menu bar is hidden on Windows and Linux or use "Firefox > Options/Preferences"