Firefox tab issues

Firefox tab issues 

Firefox saves what tabs are open when it is closed and restores them, but it doesn't seem to save the pinned tabs. Am I missing something?

Firefox is designed to keep pinned tabs across restarts automatically—even if standard session restore is turned off. When pinned tabs disappear upon closing and reopening the browser, it usually points to one of three common issues:   
geekvisit
1. The "Multi-Window" Trap

Firefox ties pinned tabs to the last window closed before exiting.   
Reddit

    What happens: If you have multiple windows open and close the main window (the one containing your pinned tabs) first, and then close a secondary window last, Firefox saves the state of that final secondary window. When you reopen Firefox, your pinned tabs are gone because the last window didn't have them.   
    Reddit+ 1

    The Fix: Always exit Firefox all at once via Menu (≡) → Exit (or Ctrl+Shift+Q), or make sure the window with your pinned tabs is the very last one you close.

2. Privacy & History Settings Overriding Session Data

If Firefox is set to clear history automatically when closing, it can wipe saved session data—including pinned tabs—upon shutdown.

    Check Settings: Go to about:preferences#privacy (or Settings → Privacy & Security).

    Scroll down to History.

    If "Firefox will" is set to Use custom settings for history:

        Ensure "Always use private browsing mode" is unchecked (Private Browsing never saves pinned tabs or session data).

        If "Clear history when Firefox closes" is checked, click the Settings button next to it and ensure Browsing & Download History is unchecked. If this box is checked, Firefox treats saved tabs as browsing history and wipes them on exit.

3. How to Get Missing Pins Back

If you lost them recently in a multi-window close, you can often recover them:

    Press Alt to show the top bar menu, then navigate to History → Recently Closed Windows.   
    Reddit

    Reopening the closed window that contained your pinned tabs will restore them to their pinned positions.   
    geekvisit

Want me to walk through how to back up your pinned tabs or session files directly?
Yes

You aren't making sense, at least to me. There is no window containing the pinned tabs. They are just tabs at the far right of the tabs panel made into icons.

By "window," I mean the main Firefox application window itself—the entire Firefox program frame sitting on your screen.

When you pin a tab, Firefox shrinks it down to an icon and docks it at the far left of your tab bar (just to clarify, pinned tabs always lock to the far left of the tab strip, while regular open tabs stay to the right).

Those pinned icons are attached to that specific Firefox application window. Here is why Firefox might be "forgetting" them when you close the program:
1. You have more than one Firefox window open when closing

If you ever have two Firefox application windows open on your desktop at the same time (for example, if a link opened in a new separate window, or if you dragged a tab out into its own window):

    If you close the main Firefox window (the big one containing your pinned icon tabs) first, and then close the second/smaller Firefox window last, Firefox considers that second window to be your "final state."

    When you launch Firefox again, it opens up matching that last closed window—which didn't have your pinned icons in it.

    The Fix: Get into the habit of closing Firefox by right-clicking the top menu or pressing Menu (≡) → Exit. This shuts down all windows simultaneously and guarantees your pinned tabs are saved.

2. Firefox is set to auto-clear data on exit

If Firefox is configured to wipe history or clear data when you exit, it treats your saved pinned tabs as part of that session history and wipes them clean:

    Open the top-right menu (≡) and select Settings.

    Click Privacy & Security on the left.

    Scroll down to the History section.

    Check two things:

        Private Browsing: Make sure "Always use private browsing mode" is unchecked (Private Browsing automatically destroys pinned tabs as soon as the app closes).

        Clear History: If "Clear history when Firefox closes" is checked, click the Settings... button next to it. Make sure Browsing & Download History is unchecked. If that box is checked, Firefox erases your pinned icons every time you close it.

If your settings are correct and you only ever have one Firefox window open, pinning a tab by right-clicking it and selecting Pin Tab should make that icon stay locked to the top-left of your tab bar permanently, even across reboots.

Oh I never touched the defaults on clearing history and such. Humans have a left/right issue, my left of the monitor's left. I take it if I just hit the close at the far upper right, I should be okay?

That explains the layout mix-up—we all have those left/right moments!

Clicking the "X" at the far upper right will work fine, provided you only have one Firefox window open at that moment.

Here is the exact catch with using the upper-right "X":

    If you have only ONE Firefox window open: Clicking the "X" works perfectly. Firefox saves your pinned tabs on the left, closes, and brings them right back the next time you open it.

    If you happen to have TWO (or more) Firefox windows open: Clicking the "X" only closes that individual window. If you close the window with your pinned tabs first using the "X", and then close a second Firefox window later, the second window overrides the first. Your pinned tabs will be lost on the next launch.

If you ever run multiple Firefox windows on screen, the safest habit is to close the whole program at once using the menu:

    Click the three horizontal lines (≡) in the upper right.

    Click Exit at the very bottom.

Otherwise, as long as you're down to just that single window on screen, hitting the "X" at the top right is all you need to do!

I meant to say my left or the monitor's left. I never open anything in a new window; no point, a new tab is so much cleaner.

That makes total sense—sticking to tabs keeps the desktop so much cleaner!

Since you only ever use a single window, hitting that "X" at the top right should preserve your pinned tabs every single time.

If you are closing that single window with the top-right "X" and those pinned tabs still vanish when you reopen Firefox, it means one of two subtle defaults is tripping things up:
1. External links opening new windows behind the scenes

Even if you never deliberately open a second window, clicking a link in another program (like an email client, PDF reader, or document) can sometimes spawn a new, separate Firefox window without you realizing it. If you then close your main window first and that extra window last, the pins disappear.
2. A corrupted session file

Firefox stores your pinned tabs in a small internal file (sessionstore.jsonlz4). If that file gets corrupted or marked "read-only," Firefox can load your pinned tabs while running, but it fails to update or save them when you click the "X".

To test if it's working properly right now:

    Right-click any normal tab and select Pin Tab so it turns into a small icon on the left.

    Click the "X" at the top right to close Firefox.

    Reopen Firefox.

If the pinned icon is right there where you left it, you're good to go! If it vanishes immediately after that test, let me know and we can clear out the stuck session file in two simple steps.

Closed it and reopened, fine. I conclude that the problem happens when there is some update or some site opens itself in a new window.

Spot on. That pinpoints the issue completely.

When a background update finishes or a site forcibly opens a pop-up in a separate window, it creates an unseen "second window." If you close your main window using the top-right "X" while that secondary window is still open, Firefox saves the secondary window as your final state—wiping out your pinned tabs for the next launch.

To lock down your setup and prevent that from happening again, here are two quick adjustments:
1. Force all external links/sites to open in tabs instead of new windows

You can tell Firefox to override websites or external programs that try to open new windows:

    Open Firefox Settings (click the ≡ menu in the top-right corner and select Settings).

    Under the General panel, scroll to the Tabs section.

    Check the box for "Open links in tabs instead of new windows."

2. Make "Exit" your shutdown habit during updates

When Firefox updates or when you suspect a stray pop-up window might be lingering:

    Use Menu (≡) → Exit instead of the top-right "X".

Using Exit forces Firefox to save all open windows together as a single session—pinned tabs included—before shutting down, completely neutralizing the multi-window trap.

OK, there is no "General" but I found a "tabs and browsing," and there what you indicated was already checked. Popups are not mentioned, and I have an extension that is supposed to stop them. It doesn't always work, but I tend to close popups right off.

That explains why those stray windows still manage to sneak in!

Pop-up ads and sites that spawn separate small windows bypass standard tab settings because the site specifically requests a "pop-up" window style with fixed dimensions. When your pop-up blocker misses one, Firefox hands it off as a separate window.

If that pop-up window is still sitting on your screen or minimized when you click the "X" on your main Firefox window, Firefox assumes you wanted to keep the pop-up as your "primary" session. When you close that remaining pop-up window second, it overwrites your main session—and wipes out your pinned tabs.
Two simple ways to permanently safeguard your pinned tabs:

    Force pop-ups into tabs as well (Hidden Setting)
    Firefox actually has an internal switch that forces all pop-up windows to open as regular tabs instead:

        Type about:config into your Firefox address bar and press Enter.

        Click "Accept the Risk and Continue" if a warning screen appears.

        In the search box at the top, paste: browser.link.open_newwindow.restriction

        Double-click the result (or click the pencil icon) and change the number from 2 to 0.

        Click the checkmark or press Enter to save.
        (Setting this to 0 tells Firefox: "Apply my 'open in tabs' rule to ALL pop-ups without exception.")

    The "Exit" Safety Net
    If a rogue window ever stays open in the background without you noticing, using Menu (≡) → Exit instead of the top-right "X" tells Firefox to save all windows together as one unified session upon closing. That way, your pinned tabs will always be right there when you reopen the browser.

This sort of thing strikes me as likely to create issues in a Firefox update.

You're completely right to be cautious—tinkering with hidden settings can easily lead to unexpected breaks or get reset during major updates.

Since modifying about:config carries that risk, the safest and cleanest approach is to keep Firefox's settings entirely on their standard defaults and rely on a quick visual check before you close the browser.
The No-Tech Fix

Before clicking the "X" at the top right, just take a quick glance at your taskbar (or dock) at the bottom of your screen:

    If you see only ONE Firefox icon active: Click the "X" with confidence. Your pinned tabs are safe.

    If you see TWO Firefox icons stacked or active: A stray pop-up or window got through. Close that small stray pop-up window first, then close your main window second.

Keeping that simple habit ensures your pinned tabs will stay right where you left them, without worrying about future updates messing anything up.

Still I like the idea of never having a new window.

That is an entirely reasonable approach—and honestly, for a clean setup, having everything constrained to single-window tabbed browsing makes navigating infinitely easier.

For what it's worth, changing that browser.link.open_newwindow.restriction value to 0 in about:config is actually a long-standing, built-in preference inside Firefox's codebase. It isn't an experimental feature or a third-party hack; it simply tells the window manager: "Take every new window request—including pop-ups—and force it into a tab in my current window."

Because it's a core preference for window routing, Firefox updates handle it gracefully without breaking or resetting it.

If you ever decide to set it, the path is straightforward:

    Type about:config into your address bar and press Enter.

    Accept the warning prompt.

    Search for browser.link.open_newwindow.restriction

    Change its value from 2 (which allows pop-ups to spawn new windows) to 0 (which forces all pop-ups into tabs).

Once that's set, any rogue website or pop-up that tries to launch a new window gets redirected right into a standard tab on your main window—keeping your desktop completely clean and guaranteeing your pinned tabs never get lost in a second window.

While I was looking at the tab options I saw a large bunch of hotkeys set by default. I am a mouse man and they often cause me unexpected surprises, so I removed all of them.

That is a great move if you primarily navigate with the mouse!

Keyboard shortcuts are infamous for triggering unwanted actions—a stray keystroke or bumped key can suddenly zoom the screen, close a tab, or open developer tools without warning.

Removing those shortcuts removes that frustration entirely, leaving you with a completely clean interface that only responds when you click with your mouse. You shouldn't see any more unexpected surprises like that moving forward.


Gemini is AI and can make mistakes.