There’s another new feature in today’s build of Firefox Nightly that I want to call attention to.

In Firefox Aurora, web developers can adjust the speed that HTML5 videos are playing at using the mediaElement.playbackRate API. This API lets websites control the speed that videos play at, whether they are in slow-motion, normal, or high-speed.

Starting today in Firefox Nightly, you can adjust the speed that videos play without needing to know JavaScript. To try this out, right-click on a video and enter the Play Speed menu:

The menu, implemented by darkowlzz, allows the user to change the playback to one of four speeds:

Slow Motion (0.5×)

Normal Speed

High Speed (1.5×)

and … Ludicrous Speed (2×)

I should note that there is still one remaining bug with the feature. Videos that are switched to the non-default playback speed will not switch back to Normal Speed using the context menu. This bug is on file and will need to be fixed before we can ship this feature on our Release channel. A simple workaround is to seek the video, as that will reset the playback speed.