I used that use case because I usually have multiple windows with multiple tabs in the background. I measured it with active windows now. Screenshots: - Both

I used that use case because I usually have multiple windows with multiple tabs in the background. I measured it with active windows now. Screenshots: - Both in background - Safari Actie - Firefox Active https://imgur.com/a/4L64ShP https://imgur.com/a/4L64ShP Conclusion: it gets even worse for Firefox. Edit: At the time of test Safari had 7 more windows open with probably 70+ tabs from my previous session that I didn't close.