Multi account containers in Firefox are fantastic. They let you separate your browsing into individual silos which means Google can’t get track you as effectively across the web.

However, it was a pain to get Youtube to log in successfully even after adding,, to the Google container site list. Every attempt to sign in bounced off to a 500 server error page.

The trick is to add ‘’ to the container site list too. This is part of the redirect when you sign into Youtube and will cause your login to fail if it tries to load outside of the google container where all the delicious cookies are!

The next issue is there is no easy way to add ad-hoc URLs to a site list of a container. To get around this:

  1. Open -you will see a 404 error but that is fine for our purposes
  2. Click Always Open in Container in the address bar
  3. Select your Google container
  4. Tick ‘Remember my Decision for this site’

Now you will be able to successfully log in to YouTube!