Firefox can be configured to restore all windows and tabs that were open when the application is closed or terminated unexpectedly. This article describes the circumstances under which your session is restored and how you can configure it.

Table Of Contents

• When session restore occurs
• Software crash
• After installing an add-on
• After a software update
• Configuring session restore
• Privacy issues

When session restore occurs

Software crash

Due to unexpected issues such as problems with a web site, software errors, or an accidental loss of power, Firefox may unexpectedly close. In these situations, Firefox can restore the pages that you were visiting when it is restarted.

• When Firefox is launched again, to re-open all windows and tabs that were displayed when it crashed, click Restore Session.
• If Firefox continues to experience errors when windows and tabs are re-opened, you can launch the browser without restoring these items. Click Start New Session.

After installing an add-on

When a new extension or theme is installed, you must restart Firefox to enable the new add-on. To restart, click Restart Firefox. All windows and tabs are re-opened when Firefox restarts and installs the new add-on.

After a software update

To apply any updates to the Firefox application that have been downloaded, you must restart Firefox. To restart, click Restart Firefox.

Configuring session restore

By default, when Firefox starts, a single window is opened, displaying your specified home page. If desired, you can configure Firefox to open all windows and tabs from your previous session:

1. At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
2. Select the Main panel.
3. From the When Firefox starts drop-down, select Show my windows and tabs from last time.
4. Click OKClose the preferences window.

Note: When the Restore Session feature is enabled, you should close Firefox through the menu. If you close each window one at a time, only the tabs in the final window that you close are re-opened upon Firefox restart.

Privacy issues

Session Restore may keep you logged in to sites that you were logged into before you closed Firefox. If someone else used your computer after you, they could access your account on these sites. If this is a concern then you should not configure Firefox to open all windows and tabs from your previous session ("Show my windows and tabs from last time" option described above).

You may also wish to disable the Session Restore crash recovery feature which is enabled by default. This will prevent restoring a previous session when Firefox is opened after an unexpected close or software crash:

1. In the Location bar, type about:config, and press EnterReturn.
   • The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!, to continue to the about:config page.
2. Find browser.sessionstore.resume_from_crash in the list
3. Double-click on browser.sessionstore.resume_from_crash to set it to false.

Based on information from Session Restore (mozillaZine KB)