How to restore Firefox’s behavior of loading all tabs at startup

Starting with Firefox 47*, Mozilla changed the way tabs are restored after a browser restart.

By default, Firefox waits until you select a tab before loading it. This “lazy loading” approach keeps the browser smooth and responsive, especially for people who reopen dozens of tabs at once.

But if you prefer the old behavior, where all your tabs load immediately when you restart Firefox, there’s a way to bring it back.

Why the change?

In earlier versions of Firefox, there was a setting in the Preferences menu: “Don’t load tabs until selected.” If you had disabled this, Firefox would happily load every tab in your previous session at startup. After upgrading to version 47 and above, Firefox reset this preference. As a result, you’ll notice only one tab loading at first, while the rest wait in the background.

How to restore the old tab loading

You’ll need to tweak Firefox’s advanced configuration settings. Here’s how:

1. In the address bar, type about:config and press Enter.

2. You could see a warning: “Proceed with Caution, Changing advanced configuration preferences can impact Firefox performance or security.”. Click “Accept the risk and continue” to continue.

3. In the search bar, type: browser.sessionstore.restore_on_demand .

4. Double click the entry to change the value from true (default) to false.

5. Close the about:config tab. The changes are saved automatically.

That’s it! Next time you restart Firefox, all your tabs will load immediately.

*At the time of writing this, we’re at version 143, but hey, I found time to blog again, so be nice. 😉

Picture by Growtika