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

Firefox multiprocess is not enabled.

  • 6 replies
  • 8 have this problem
  • 1 view
  • Last reply by smcc42

more options

Firefox is very slow when multiple tabs are open. Multiprocess is not enabled. How can I enable it?

Firefox is very slow when multiple tabs are open. Multiprocess is not enabled. How can I enable it?

All Replies (6)

more options

Hi   !

Would you try this please :

Type in the address bar   about:config   (press Enter) (promise to be careful, if asked) Type and look for the preferences :

browser.tabs.remote.autostart and browser.tabs.remote.autostart.2

And set both values to   true


There is a chance that multiprocess didn’t turn on because of incompatible add-ons.

To force-enable multi-process functionality in Firefox :

(It's recommended that you backup your user profile before you do)

Right-click and select  : New => Boolean.

Name it : browser.tabs.remote.force-enable Set its value to true

Note that force-enabling is not encouraged.

more options

What message do you see on the "Help -> Troubleshooting Information" page?

  • "Help -> Troubleshooting Information" page under Application Basics: Multiprocess Windows.
more options

Happy112 said

Hi   ! Would you try this please : Type in the address bar   about:config   (press Enter) (promise to be careful, if asked) Type and look for the preferences : browser.tabs.remote.autostart and browser.tabs.remote.autostart.2 And set both values to   true

There is a chance that multiprocess didn’t turn on because of incompatible add-ons.

To force-enable multi-process functionality in Firefox :

(It's recommended that you backup your user profile before you do)

Right-click and select  : New => Boolean.

Name it : browser.tabs.remote.force-enable Set its value to true

Note that force-enabling is not encouraged.

I had already checked that the browser.tabs.remote.autostart options were set to "true".

more options

cor-el said

What message do you see on the "Help -> Troubleshooting Information" page?
  • "Help -> Troubleshooting Information" page under Application Basics: Multiprocess Windows.

Multiprocess Windows 0/1 (Disabled by add-ons)

more options

smcc said

Multiprocess Windows 0/1 (Disabled by add-ons)

I don't know if you have many add-ons, but would you take a look at this please :

https://blog.mozilla.org/addons/2016/09/07/help-make-add-ons-multiprocess-compatible-with-add-on-compatibility-reporter/

I'm not sure about this add-on, but you could give it a try :

https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/

Modified by Happy112

more options

Happy112

My extensions page already tells me which add-ons are incompatible with Multiprocess and I have disabled all of these which seems to have solved the problem!

Modified by smcc42