How to Analyze Website Power Usage in Firefox
Mozilla recently launched Firefox 104, and with it a new Developer Tools option for analyzing the power consumption of websites. The feature is limited to Windows 11 and Apple M1 devices.
Device power consumption has been the focus for some time, but not about which activities require the most power on a device. The information can be useful, especially for mobile users who sometimes or always use their devices on battery power. If the battery is getting low, one can extend the battery life by avoiding power-hungry activities on the device.
To measure the energy consumption of websites in Firefox, Firefox 104 or later is required. This is the only prerequisite, other than running Firefox on a Windows 11 or Apple M1 device.
Note: Data is submitted to the Firefox website, where it is displayed.
Here are step-by-step instructions for checking a website’s power usage in Firefox:
- Open the website you want to analyze.
- Select Menu > More Tools > Web Developer Tools or use the keyboard shortcut Ctrl-Shift-I to open the interface.
- Optional: I suggest moving the interface to the bottom of the Firefox window by selecting Menu > Dock to Bottom.
- Switch to the Performance tab in the developer tools interface.
- Select the Power option under Settings.
- Activate the “Start recording” button.
- Use the website as you normally would.
- Activate the “Capture recording” button to complete the recording.
- The Firefox Profiler website is loaded automatically.
- Locate the power readings at the top (you may need to scroll down to find them).
Firefox lists the amount of CPU package, CPU cores, and iGPUs powering the website required during use. Move the mouse over the data to get the actual reading, for example, 6.89 W at the 10 second mark.
The new profiler option is missing information. Is 6W a lot when it comes to websites? There is no average that Firefox displays, which might be helpful, or different power consumption ranges that reveal whether a site is using more power than the average site or less.
For now, Firefox users are left alone in the quest. Checking multiple sites can reveal missing information, so it becomes easier to determine if a site is consuming more power than average.
Now you: How much power do your favorite sites need?