Different browsers consume different amounts of energy depending on their features, settings, and usage patterns. However, some studies suggest that browsers like Microsoft Edge, Mozilla Firefox, and Apple Safari are more energy-efficient than Google Chrome, especially when running on laptops or other portable devices. It may be worth experimenting with these browsers and comparing their energy usage to find the one that works best for you.
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From the OS, switching your power plan, using the integrated GPU(?) and reducing brightness can help reduce overall power consumption whilst in-use. External displays can be set to sleep after ie. 4 hours, and completely powering down or putting devices to sleep may help when they are not in use.
The new version of MS EDGE has become clearer about energy savings Optimize Performance to access on your EDGE type edge://settings/system in the address bar.