Firefox has a feature that allows it to find the pages you were visiting in case of browser or system crash. Sometimes, however, that restoration is not very accurate, the backup sessions state taking place only every 15 or 10 seconds. You can reduce this interval to 5 seconds and in this tutorial I will show you how to do that.
To get started follow steps below
Step 1: Launch Mozilla Firefox
Step 2: Enter about:config in the address bar and press Enter on your keyboard
Step 3: Click I’ll be careful, I promise!.
Step 4: In the Filter field, type the command browser.sessionstore.interval.
Step 5: Double click on the option browser.sessionstore.interval from the results
Step 6: Change the value in ms, 15000 (15 seconds) by 5000 (5 seconds) then click the OK button to save changes
Step 7: Now restart your Firefox for changes take effect.