At the top of the Firefox window, click the Firefox button, go over to the History menu and select Clear Recent History....

History Win1

Select how much history you want to clear: Click the drop-down menu next to Time range to clear to choose how much of your history Firefox will clear.

History Win2

Next, click the arrow next to Details to select exactly what information will get cleared. Your choices are described in the What things are included in my history? section above.

History Win3 Fx11

Finally, click the Clear Now button and the window will close and the items you've selected will be cleared. How do I make Firefox clear my history automatically?

If you need to clear your history every time you use Firefox, you can set it to happen automatically on exit so you don’t forget.

At the top of the Firefox window, click on the Firefox button and then select Options Select the Privacy panel. Set Firefox will: to Use custom settings for history. Custom History Fx21 Win7 Check the box for Clear history when Firefox closes. History Win4 To specify what types of history should be cleared, click the Settings... button next to Clear history when Firefox closes. In the Settings for Clearing History window, check the items that you want to have cleared automatically each time you quit Firefox.

History Win5

After selecting the history to be cleared, click OK to close the Settings for Clearing History window. Click OK to close the Options window

Hope this will help you thanks.

please see this

Clear your browsing history and other personal data on Firefox for Android

Hello Aman, The question is regarding the web browser. Thanks, Dyvik