Computer science, programming, and whatnot.

Playback speed on Substack

August 25, 2023 back to posts

I'm subscribed to a Substack that I enjoy, but the Substack video player doesn't haveany options for adjusting the playback speed of the video. Often, I prefer 1.33 speed, or even 1.5 depending on the content. This has been a little annoying, and what I thought was the alternative, downloading the video (somehow) and playing it in some player which does support changing the speed was a little too much work.

However, HTML5 video elements do support changing the playback speed, and while it's not easy to do as a user, it's very straight-forward for a developer. Here's how (on Firefox; I assume other browsers are similar):

  1. Select the video element with the DOM inspector
  2. Right click on the element and select "Use in Console". This opens the console with temp0 bound to the video player element.
  3. Execute temp0.playbackRate = 1.33 (or whatever speed you want)

That's it!

Here's the MDN docs on the playbackRate property. It says that if you set playbackRate to a negative value, the video will play backwards (!). This, however, doesn't seem to always be supported.

Any remarks can be sent to my public inbox.

Thanks for reading.

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