I've been using Video Speed Controller and it makes adjusting playback speed on any HTML5 video effortless. The fine-grained control and keyboard shortcuts are very convenient for lectures and tutorials. It remembers settings per site and feels lightweight, reliable, and smooth without interfering with normal viewing experience at all sessions.

Do not install this extension! This is not the original Igrigorik author! See their GitHub for confirmation.

One-starring to spread awareness that both the extension and the author of this Firefox port has no ties to the original project, as by Igrigorik's disclaimer on their Github issues page. Avoid installing/enabling since this is very suspicious behavior.

Sketchy af. The original author disavow this add-on. github.com/igrigorik/videospeed/issues/1511

I'm glad to see the original developer's version on the Firefox Add-ons Store, not just a fork. The forked version caused performance issues that slowed down Firefox for years and was left unmaintained for a long time, so I hope those problems have been resolved in this original release.

As of now, the latest version of the Video Speed Controller add-on for Firefox is 0.9.5, released in October 2025. I would appreciate it if the more recent version, 0.10.2, could also be made available for Firefox.

works