Video Speed Controller — carsso

Video Speed Controller gives you fine-grained control over any HTML5 video or audio element, on any site — YouTube, Netflix, Prime Video, Coursera, podcasts, even local files.

Most players hide or artificially limit playback speed. This adds a small draggable overlay on the player plus keyboard shortcuts, so changing speed becomes effortless enough to do constantly.

Default shortcuts

• S — decrease speed
• D — increase speed
• R — reset to 1x
• Z — rewind 10 seconds
• X — advance 10 seconds
• G — toggle between current and preferred speed
• V — show or hide the controller
• M — set a marker at the current position
• J — jump back to the marker

Features

• Speed from 0.07x to 16x, in configurable steps
• Per-site speed rules — always 2x on lecture sites, for example
• Per-site disable
• Remembers your last speed across tabs and sessions
• Speed fightback: re-applies your speed when a player tries to reset it
• Every shortcut remappable, including modifier combinations
• Custom CSS for the overlay

Privacy

This add-on collects nothing and transmits nothing. Your settings stay in Firefox's own storage.

About this build

Video Speed Controller was created by Ilya Grigorik, who develops and publishes it for Chrome. The original extension is on the Chrome Web Store, and its source lives at github.com/igrigorik/videospeed.

It is Chrome-only by design. A Firefox port was considered upstream and declined, for sound reasons: it is not a manifest-only change, and it carries an ongoing release, review and site-compatibility cost that would land on its author.

This listing is an unofficial Firefox build of that work, and exists to take that cost on rather than ask him to. It takes each upstream release unmodified, applies only the Firefox-specific adjustments needed to run on Gecko, verifies the result in a real Firefox, and publishes it here. Every line of extension code is Ilya Grigorik's, under the MIT licence. This build is not affiliated with or endorsed by him.

The build tooling and the exact adjustments are public at github.com/carsso/videospeed. Please report anything about speed behaviour upstream, and packaging or Firefox-specific problems here.