I'm not sure exactly what the difference (if any) is between Chrome's dev tools and Chromium's dev tools, but Opera AFAIK uses Chromium's tools and the battery

I'm not sure exactly what the difference (if any) is between Chrome's dev tools and Chromium's dev tools, but Opera AFAIK uses Chromium's tools and the battery life on my 12" Macbook under normal web browsing in Opera (with adblocker and battery saver turned on) routinely exceeds 10 hours. I do a bit of light web development work every now and then but I'm not really qualified to comment on how good the developer tools in question actually are. To me, they seem to have some nice features and they do what I need.