Stop Firefox From Always Restoring Your Previous Session

Firefox keeps reopening last night's windows and tabs every time it launches, even when you closed them on purpose. The usual causes are the Startup setting, crash recovery, and an extension that manages sessions.

Clear the Startup checkbox first. If the old session still returns, change browser.startup.page in about:config, then test your extensions one at a time.

In this guide, I have covered:

Turn off the Startup option that reopens your tabs

You closed Firefox on purpose, opened it again, and the same windows came back. That is session restore working as designed: Firefox saves your last session and reopens it at launch.

The switch sits in Settings, under General, in the Startup section. One checkbox turns it off.

1. Open the menu, then select Settings.
2. Select General in the Settings sidebar.
3. Scroll to the Startup section.
4. Clear the checkbox beside Open previous windows and tabs.
5. Close Settings and restart Firefox.

You’ll know it worked when Firefox opens your home page or start page instead of last night’s tabs. Open an extra window, close it, restart, and check again if you want proof.

Some older builds show a When Firefox starts dropdown in place of the checkbox. Pick any option other than Restore previous session, then restart to confirm the change.

Change the startup preference in about:config

The checkbox is missing, greyed out, or simply will not stick. That usually means a preference or policy is overriding it, and Firefox’s advanced configuration page changes the same behavior at the source.

Mozilla’s official support guidance for restoring previous sessions explains how startup restoration and crash recovery are connected, which helps when you are choosing which preference to change.

1. Open the menu, then select Settings.
2. Scroll to the bottom of the General panel and select Advanced.
3. Select Config Editor near the bottom of the Network and Disk Space section.
4. Accept the warning about entering advanced settings.
5. Search for browser.startup.page.
6. Change its integer value from 3 to 0.
7. Search for browser.sessionstore.resume_from_crash.
8. Change its Boolean value from true to false.
9. Restart Firefox and check which page or tabs appear at startup.

Setting browser.startup.page to 3 is what tells Firefox to reopen the previous session. A value of 0 sends startup back to your home page instead.

The second preference controls the automatic restore after an unclean shutdown. Set it to false, restart, and you’ll know it worked when a normal restart opens one clean window with no older tabs trailing behind it.

Changing browser.sessionstore.resume_from_crash disables automatic crash recovery as well as normal startup restoration. You can still reopen a previous session manually from the History menu when you need it.

Check whether crash recovery is restoring Firefox

You cleared the checkbox, restarted, and the old tabs came back anyway. Firefox may have decided the last shutdown was a crash, and crash recovery reopens the session no matter what the Startup setting says.

1. Close all Firefox windows.
2. Start Firefox again.
3. Check whether the old windows and tabs appear even though Open previous windows and tabs is clear.
4. If they appear, repeat the about:config procedure and confirm that browser.sessionstore.resume_from_crash is set to false.

Tabs that stay away after a normal close but return after a forced quit point straight at crash recovery. That is the pattern to watch for.

A normal shutdown records the current session. Force-quitting Firefox can interrupt that process and leave recent tab changes unrecovered, so close the browser normally when you want its session history saved.

Test for extensions that restore tabs

Settings look right, crash recovery is off, and the tabs still return. At that point an extension is the likely culprit, since session managers, tab savers, and workspace add-ons often reopen tabs at launch from their own settings.

1. Open the menu, then select Add-ons and Themes.
2. Select Extensions.
3. Disable extensions related to sessions, tabs, workspaces, or automatic reopening.
4. Close and restart Firefox, then check whether the previous session still opens.

If the behavior stops, you have found the responsible extension. Adjust its own restore options, then re-enable the remaining extensions one at a time so you do not lose anything you still use.

TIP: If you want to keep an extension but stop it from reopening tabs at startup, open that extension’s options after the test and clear its automatic session or launch-restore setting. You’ll know it worked when the extension stays enabled and a restart still opens a clean window.

Restore one session manually when needed

Automatic restore is off now, but the command itself is still there. When you actually want last night’s tabs back, one menu item brings them back without touching your startup setting.

1. Open the menu.
2. Select History.
3. Select Restore Previous Session.

If that entry is not available, look under Recently Closed Windows or Recently Closed Tabs. A manual restore is a one-off action, so Firefox opens normally the next time you launch it.

Dealing with missing tabs rather than unwanted ones? That is a different problem, and the fix is to re-enable session restore and recover tabs that did not save.

Reset Firefox’s startup settings

The Startup controls stay greyed out and nothing you change sticks. A Firefox refresh rebuilds preferences from defaults while keeping your bookmarks, saved logins, and history.

1. Open the menu, then select Help.
2. Select More Troubleshooting Information.
3. Select Refresh Firefox in the Firefox Refresh section.
4. Confirm that you want to reset Firefox.
5. Restart Firefox and check the Startup option again.

You’ll know it worked when the Open previous windows and tabs checkbox is editable again and stays cleared after a restart.

For the complete reset procedure and what Firefox preserves, see Reset Mozilla Firefox Browser Settings on the Computer.

RELATED: Clear Browsing History from Mozilla Firefox