Just putting this out there for people having trouble with local files. This was a change by Firefox and it can be fixed.

Go to the add-ons page (about:addons or ctrl+shift+a), click Extensions on the left, find Video Speed Controller on the list, click the 3 dots, Manage, click the "Permissions and data" tab at the top, and toggle "Access local files on your computer". This works for a lot of other addons that recently broke for local files.

Great extension but as of Firefox version 153, there has been an update by Firefox that no longer allows you to use your shortcut keys to change playback speed when viewing local video files that you drag into your browser. This isn't a frequent use but sometimes it's nice when you want to watch a local video and use Firefox's PIP feature for watching and browsing.

If anyone knows a fix, please feel free to let us know. Thank you in advance.

I love focused extensions with a clear purpose like this.

Because I'm slightly paranoid I did a quick check of the source of v0.6.3.3. The code is minimal and clean, without any wasteful bells and whistles, and doesn't do anything else than the thing it promised to do.

I should note that it has not been updated in 5 years at this point. I personally consider that a *good* thing because that suggests I don't have to worry about unexpected changes or functionality being taken away. It also means the extension predates vibecoded slop, which is a bonus. On the other hand, there are quite a few open issues on the github tracker, and if you run into one of them it's unlikely to be fixed, so YMMV.

But in my use-case (desktop browser) it works very well.

100% worth it and works seemlessly

Let's me speed up a long YouTube video so I can watch it faster. Reload the page you want to use it with in case you don't see it.

Works flawlessly for me. I run Firefox on Ubuntu. It also worked well for me on Windows and Firefox before I switched to Linux.

I can't speak to how it works on other sites, but my teacher added additional videos to a Canvas post that had no ability to fast forward and this is saving me. It can be a bit janky but it's nothing I didn't expect from an extension adding a non-native feature. (Though, edit, the clunkiness went away once I used the keyboard shortcuts!)

perfect

"Excellent and very customizable. Works on most websites with video, making it universal (unlike extensions for specific sites only, e.g., YouTube). Can configure keyboard shortcuts as well as speed jump increments."


"One of the best add-ons out there! Controls speed of every motion picture, even GIF! You can set your own shortcuts, so I set the same as YouTube. Now I can easily speed up to 6x or even more on YouTube!"

For those getting black screen with Amazon Prime Video - set the speed to what you want and disable the controller overlay and it'll work right away. You can use the shortcuts instead as well. In settings, you can permanently disable controller overlay by default.