I often open links in new tabs and come back to them later without noticing that it never quits loading so this may be handy.I installed it this morning and it has kicked in a couple times. “Some pages will not finish loading because of internal problems or the use of ad-blockers and other filtering tools.This extension stops pages from loading indefinitely and slowing the browser.” Address : addons.mozilla.org/en-US/firefox/addon/killspinners/