How to Permanently disable Private Window option in Firefox Quantum (v.62)

Question

I dont want to have Private Browing option available with my Firefox browser. I found an extension for v.44, But this is not compatible with Firefox Quantum (v.62) https://superuser.com/questions/1044722/how-to-remove-private-browsing-from-firefox-v44

I found a something for Chrome at: How to disable Chrome's Incognito Mode?

Can I get similar solution for Firefox Quantum??

Answer 1

Edit dated 20200418: still valid in Firefox 75

Ensure that Firefox is totally not running

Open a terminal and change directory to /usr/lib/firefox/distribution. In case the distribution folder does not exist, create it.

Run sudo touch policies.json

Run sudo nano policies.json

Paste in the following text

{
  "policies": {
    "DisablePrivateBrowsing": true
  }
}

Save policies.json

Now, when you next open Firefox, you won't see the Private Browsing option.

Of course, if someone else has sudo access to your machine this exercise maybe pointless. And I don't know if you'll need to do this each and every time Firefox updates.

References:

• Customizing Firefox Using policies.json

• mozilla/policy-templates