You can't delete Firefox's profile system. Every bookmark, password, and setting lives in that folder, and the browser won't start without it. What you can turn off is the new Profile Manager UI in the menu.
One preference does it: set browser.profiles.enabled to false in about:config and the Profiles entry disappears. Your data stays where it was, and about:profiles still works.
In this guide, I have covered:
Contents
What the Firefox Profile System Is and Why You Can’t Remove It
If you want Firefox’s profile system gone, here’s the honest answer: you can’t remove it. Every Firefox install runs on a profile, a folder on your computer that holds your bookmarks, history, saved logins, extensions, site permissions, cookies, and custom settings. Without that folder, Firefox will not start.
A Mozilla Support volunteer confirmed this in a recent thread: delete the profile folder outright and the browser refuses to launch.
Your profile is also what carries your settings between devices when Firefox Sync is turned on.
What you can turn off is the new Profile Manager UI: the Profiles entry at the top of the 
menu and the about:profilemanager page. Hiding it does not delete anything. It only removes the switcher Firefox added on top of the old system.
Disable the New Profile Manager UI in Firefox
Want the Profiles entry out of your menu? One boolean preference does it. Set it to false and the entry disappears immediately, with no restart.
- Open Firefox and type about:config in the address bar, then press .
- Click on the warning page.
- In the search box at the top of the preference list, type browser.profiles.enabled.
- Click the Toggle button at the right end of the row to switch the value from true to false.
You’ll know it worked when the Profiles entry is gone from the menu and about:profilemanager stops loading the new manager page. No restart, no sign-out.
Firefox still uses your existing profile in the background. Toggling this preference only hides the user-facing Profile Switcher, so your bookmarks, passwords, and history stay intact.
Switch Firefox Profiles From the Command Line
Need to juggle more than one profile? The older command-line route still works, even with the new UI hidden. Nothing you changed above affects it.
- Close Firefox completely (all windows).
- Open Command Prompt on Windows, or Terminal on macOS or Linux, and run firefox -P. On Windows you may need the full path, for example "C:\Program Files\Mozilla Firefox\firefox.exe" -P.
- Firefox opens the legacy profile chooser where you can create, rename, or delete profiles.
This is the same dialog older Firefox versions used, and browser.profiles.enabled does not gate it.
Each profile keeps its own bookmarks, logins, and history, so a work profile and a personal one never mix. If you only need a one-off session that saves nothing, a Private Window in Firefox is quicker than building a second profile.
TIP: Preference changes live inside the profile you made them in. If you switch to a second profile with firefox -P, set browser.profiles.enabled there too.
Open the Legacy Profile Manager Page
Prefer something you can reach from the address bar? Firefox still ships a built-in page that lists every profile on the machine. It looks plain, but it works whether the new UI is on or off.
- Type about:profiles in the Firefox address bar and press .
- Use the buttons under your default profile to launch a new browser instance with that profile, rename it, or delete it.
This is the safest option if you only want to inspect profiles now and then and do not want the menu entry sitting there all the time.
Re-enable the Profile Manager UI Later
Changed your mind? Flipping the same preference back takes about ten seconds.
- Go to about:config in the address bar.
- Search for browser.profiles.enabled.
- Click the Toggle button to switch the value back to true.
The Profiles entry reappears at the top of the menu the moment you toggle it on.
Frequently Asked Questions
Can I completely delete the Firefox profile system?
No. Firefox needs a profile folder to store bookmarks, history, logins, and settings, and without one the browser refuses to start. What you can disable is the user-facing Profile Manager UI (the Profiles menu entry and the about:profilemanager page), not the underlying profile storage.
Will disabling the Profiles menu delete my data?
No. Toggling browser.profiles.enabled to false only hides the new switcher. Your profile and everything inside it stays intact, and you can still reach profile management through about:profiles or the firefox -P command.
Does Firefox need a restart after toggling the preference?
No. The change takes effect immediately. Open the menu and the Profiles entry is gone, and about:profilemanager stops loading the new manager page.
What is the difference between about:profilemanager and about:profiles?
about:profilemanager opens the new Profile Switcher, which only loads when browser.profiles.enabled is true. about:profiles opens the older, basic profile list, which is always available regardless of that preference.
Bottom line: hide the switcher if it gets in your way, but leave the profile folder alone. That folder is your data.
