You can restore all previously closed tabs and windows in Firefox web browser. Here’s how to do it.
Restore the previous session using the Firefox menu.
Click the menu button on the right side corner of your toolbar.
Select Restore Previous Session.
Configure Firefox to restore the previous session at startup.
You can also configure Firefox to restore all previous sessions each and every time you start Firefox. Here’s how to configure session restore at startup.
Click the menu button and select Options. Alternatively, you can also access the page by directly entering about:preferences in the address bar.
Select the General panel.
In the General panel, below Startup select Restore previous session.
Changes you have made will automatically be saved. You can close the page.
Privacy issues to remember.
Configuring session restore may keep you logged in to sites that you did not log out before you closed Firefox. If someone else used your computer after you, they could access your account on these websites. Remember this before configuring Firefox to restore the previous session at startup.