BetterMediaKeys is a free Chrome extension developed by TroyWare that allows you to use your media keys to navigate YouTube chapters or videos. With this extension, you can easily navigate YouTube chapters even when your browser is not in focus.

In addition to chapter navigation, BetterMediaKeys also enables you to use your media keys to restart the currently playing video or skip to the next video in the queue. This feature is especially useful for videos without chapters, as it allows for seamless control over your YouTube playback.

One notable feature of BetterMediaKeys is that it replaces the video title with the current chapter title on the mini player. This is particularly beneficial for single video music playlists, as it allows you to see the current song title instead of the playlist video title.

To ensure compatibility, please make sure you have the 'MediaTrackPrevious' and 'MediaTrackNext' keys available on your keyboard. Without these keys, the extension will not function properly.

It is worth mentioning that BetterMediaKeys does not alter the functionality of playlists on YouTube. You will not lose any playlist features after installing the extension, apart from the mini player video title being replaced by the current chapter title on videos with chapters.