An idle web app will use up just as much battery as an idle native app. Idle apps can still vary in how much battery life they consume. I've seen some backgrou

An idle web app will use up just as much battery as an idle native app. Idle apps can still vary in how much battery life they consume. I've seen some background apps that don't appear to be using any CPU (i.e. "0%" utilization) but actually have high-frequency timers which will wake the CPU every time they fire. Waking the CPU is bad news because it kicks it out of the low-power C-states and thus eats more battery. If you're on Windows try running 'powercfg /sleepstudy' and you might find some interesting power-hungry behavior from even "idle" apps: https://blogs.windows.com/windowsexperience/2014/06/26/sleep-study-diagnose-whats-draining-your-battery-while-the-system-sleeps/ https://blogs.windows.com/windowsexperience/2014/06/26/sleep... On Linux, you can use 'powertop' for the same purpose, though I've found powertop is more useful since it shows more raw data and makes fewer assumptions.