On Chrome browser, you can select which extensions are active in private mode (incognito). How to do the same in Firefox please? (By default Firefox allows all add-ons in Private mode).


1 Answer 1



At least through version 63, Firefox lacks a native feature to selectively control which add-ons are allowed in private mode; the enabled/disabled status of each is the same in private mode (although all add-ons are required to comply with the private mode rules regarding data retention). But there's a workaround to accomplish what you want.

You can have more than one profile, and each profile is independent as far as what add-ons are installed or enabled.

  • Create a new profile, including just the add-ons you want in private mode. If you're in Firefox, enter about:profiles in the URL window, and that has an option to create a new one.
  • Create a shortcut to launch Firefox in private mode using that profile. The command line would look like:

    firefox -private -P "new_profile_name"

Bookmarks and Other Profile Content

As you note in a comment, this still isn't exactly the same as the Chrome feature because Chrome retains other settings and information, like bookmarks, in incognito mode. So you need a second workaround if you want that similarity.

You can do that with controlled syncing. Firefox has a feature that allows you to selectively synchronize most of what reflects "you": preferences, add-ons, log-ins, history, bookmarks, etc. It can be accessed through Preferences | Firefox Account.

You obviously don't want to synchronize some of those options with a private mode profile. For example, add-ons (since you want them to be different). You also probably don't want to sync history (Firefox won't retain the history when you finish the session, but I'm not sure whether it would sync the visited sites during the session, and that would defeat the purpose of private mode). Login information is another thing private mode erases at the end of the session, so you probably don't want to sync that.

In any profile, the sync selections control what that profile shares with, and updates from, your other profiles. So you can have several computers that share everything, and a private mode profile that only shares and updates certain options.

Syncing uses an email address as a unique identifier. You create an account tied to an email address. Firefox will remember the account ID for you and automatically sync when you start or there is something to update (or you can activate and deactivate syncing manually).

If you will want a lot of add-ons in private mode, you might want to initially sync them just to install all of your current add-ons in the private mode profile. Then deselect add-ons for syncing, and remove or disable the ones you don't want active in private mode.

Profiles vs. Portable Firefox

Firefox, itself, is like a browsing "engine". Everything you do that makes it different for you is stored in your profile, which is located separate from the Firefox application software. That includes preferences you set, add-ons, the history of sites you visit, your bookmarks, etc. When you update Firefox, it updates the software, but doesn't touch your profile (well, except to verify that all of your add-ons are still compatible).

This also allows things like having multiple users on one computer, or a user with multiple profiles, while requiring only one copy of the Firefox software to be taking up space on your drive. Your "user experience" comes from the Firefox application using your profile.

Downloading a separate portable Firefox, as you suggest in a comment, would produce sort of a similar result, but it's not the same. That would add another copy of the Firefox application just to get another profile. There are also some subtle differences in the portable version, like it can have only a single profile.

  • Thank you. Some follow-ups: 1. I looked into this profile option but it seems like it will have it's own bookmarks too. Any way to access the same bookmarks 2. This profile option seems the same as downloading a separate portable Firefox and configuirng that with no add-on. Is that correct?
    – get_going
    Nov 14, 2018 at 13:30
  • @get_going, good points. Too much to address in a comment, so I'll expand the answer.
    – fixer1234
    Nov 14, 2018 at 20:22
  • Hi fixer1234, thanks for the detailed explanation. I will try out your suggestions and report back. Meanwhile, can you tell me something. I'm sure that developers of Firfox would have give this some thought. And you state that, "add-ons are required to comply with the private mode rules". Is that really the case in reality? Can I assume that no add-on would surreptitiously record my sites in private made, or maliciously store login info?
    – get_going
    Nov 15, 2018 at 0:37
  • @get_going, I'm not familiar with what screening developers need to go through to get their add-ons in the Mozilla add-on repository (grabbing add-ons off the Internet outside of that is at your own risk). Private mode is pretty straight-forward. Certain things, like history, cookies, etc. are defined as stuff that is supposed to be deleted upon exit; it's just prescribed behavior. There is no reason for a developer to make their add-on work differently. Doing things surreptitiously or maliciously defines an add-on as malware, which is completely different. (cont'd)
    – fixer1234
    Nov 15, 2018 at 1:11
  • 1
    All browser developers have controls in place to try to pre-screen for that and to remove offending add-ons if discovered, and your antivirus software screens for that. I don't know if 100% of Firefox add-ons are open-source, but I think most of it is. It's tougher to hide malware in code that anyone can look at. So, like any software you load on your computer, there is some chance that malware will slip through, but add-ons from the browser's repository are generally as safe as you'll find from any trusted source.
    – fixer1234
    Nov 15, 2018 at 1:12

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .