Is there a way to identify the busy (CPU-consuming) tab in Firefox? [duplicate]

Solution 1:

As you can see here it's on their list for 7 years.

Electrolysis is available in the nightly version roughly since the beginning of 2014, and that seem like the only possibility at the moment.

Solution 2:

Via a suggestion from HN user ~liminal, a short sampling (~10 seconds) using the Developer Tools 'Profiler' might be helpful in such situations.

I've just tried this in Firefox 33.0, and many of the report-rows include a related source domain, which may help identify the tab responsible. (Unfortunately, many of the report-rows are related to domains like apis.google.com, which might be in use in any given tab.) Still, it's a start.