Comparing Firefox, Chrome and Safari battery life on macOS.

With the new Firefox being released, I thought I would revisit these three browsers for their effect on battery life.

• I completed the experiment using a Macbook 11" from 2011. This is the "couch computer" at our house.
• It is used every day for Youtube, Netflix, Plex, Facebook, etc. It runs macOS 10.13.1. It has a 3rd party battery in it (I replaced it myself), which is about a year old.
• I turned off all energy-saving features, like screen-dimming, sleep mode, etc.
• Then I ran the browser in 'private' mode, and had it loop through videos on my Youtube channel, until the battery died.
• I recorded it using an iPad. The setup looked like this:

Here's the testing, with time-lapse videos:

First, Firefox. Started at 8:53, computer turned off at 10:16. Making it 1 hour and 23 minutes (83 minutes)

Second, Chrome. Started at 3:59, computer turned off at 5:59. Giving it approximately 2 hours (120 minutes)

and finally, Safari started at 5:53, and computer turned off at 8:13. 2 hours and 20 minutes (140 minutes)

Firefox: 83 minutes
Chrome: 120 Minutes
Safari: 140 Minutes

Some post-experiment thoughts:

• I should try this on a Windows 10 laptop. That's going to be a future project.
• How about a newer Mac?
• This is not "scientific" enough, as Youtube watching really doesn't stress the browser much. I might try and find a more representative browser benchmark and re-run the experiment.
• It would probably be a good idea to run the experiment multiple times and average out the times.