If you don't want to drain your Windows 11 laptop's battery while out and about, Firefox can show you how much power specific websites use up. Here's how it works:

- In Firefox, go to the website you want to measure and click the three dots top right.

- Select 'Tools', then 'Web Developer Tools', and open the 'Performance' tab.

- Click 'Start recording' and hover your mouse over the power graphs to see how many watts of power the website is using.