3 ms·

Try the profiler. https://profiler.firefox.com/docs/#/./guide-getting-started?id=capture-a-profile https://profiler.firefox.com/docs/#/./guide-getting-started?.

• ciupicri 4y ago
  If I'm not mistaking that's for investigating a single tab, while I have thousands of tabs with various websites.
  • kbrosnan 4y ago
    That can profile the whole browser as a unit. It does try to record only active threads. There are ways to set it to record everything. https://chat.mozilla.org/?#/room/#perfteam:mozilla.org https://chat.mozilla.org/?#/room/#perfteam:mozilla.org is good place to access the people who know more about the profiler than I.