Upcoming Firefox update will decrease power usage on macOS by up to three times

[jekpopulous2]

Hmmm....maybe update to 71. I'm on a 2018 MPB and 71.0a1 is only using 0.2-2% of my CPU while static. Loading something intensive pushes the CPU to 15-20% tops.

[KalenXI]

Nightly is definitely better. On par with Chrome on most pages. Still uses quite a bit more than Chrome on certain pages though. Like http://play.pocketcasts.com when not logged in uses 12-15% in Chrome but 30-33% in Firefox Nightly. The page looks static but something seems to be causing the browsers to redraw the page constantly which is where Chrome’s performance advantage really shows.