I can't reply to the dead comment here, but if you're looking for a tunable version of this functionality try https://addons.mozilla.org/en-US/firefox/addon/aut

I can't reply to the dead comment here, but if you're looking for a tunable version of this functionality try https://addons.mozilla.org/en-US/firefox/addon/auto-tab-discard/ https://addons.mozilla.org/en-US/firefox/addon/auto-tab-disc...