In Mozilla Firefox, how do I extract the number of currently opened tabs to save elsewhere?

Question

I want to automatically count the number of tabs that are open in Firefox so that I can track this over time.

It is therefore not enough that I can get an add-on that di

Answer 1

Open the about:telemetry link.

Under scalars you will find the browser.engagement.max_concurrent_tab_count key whose value gives you the number of open tabs.