Firefox has offered the same in the Aurora &#x2F; Developer Edition channel since July 2014: <a href="https:&#x2F;&#x2F;hacks.mozilla.org&#x2F;2014&#x2F;07&#x2F;event-listeners-popup-media-sidebar-cubic-bezier-editor-more-firefox-developer-tools-episode-33&#x2F;" rel="nofollow">https:&#x2F;&#x2F;hacks.mozilla.org&#x2F;2014&#x2F;07&#x2F;event-listeners-popup-medi...</a><p>More docs on MDN: <a href="https:&#x2F;&#x2F;developer.mozilla.org&#x2F;en-US&#x2F;docs&#x2F;Tools&#x2F;Page_Inspector&#x2F;How_to&#x2F;Work_with_animations" rel="nofollow">https:&#x2F;&#x2F;developer.mozilla.org&#x2F;en-US&#x2F;docs&#x2F;Tools&#x2F;Page_Inspecto...</a>