Pause Key by cyb

Press Play/Pause and every tab that's playing stops. Press it again and only the video or song you started last comes back: not the autoplaying clip in another tab, and not everything at once.

How it decides
- Anything audible playing in any tab (YouTube, embedded players, podcasts, music sites…): Play/Pause pauses all of it.
- Nothing playing: Play/Pause resumes the media you last started yourself, with a click or key press on the page.
- Muted autoplay videos are ignored, so they can't swallow your key press.
- An explicit Pause or Stop (a phone call through KDE Connect, unplugged headphones) only ever pauses, never starts anything.

It uses Firefox's own media-key support, so it works while Firefox is in the background, on Linux, Windows and macOS. Nothing to install besides the extension.

No media key? Map any key to Play/Pause:
- KDE Plasma: System Settings → Shortcuts → Media Controller → Play/Pause media playback.
- GNOME: Settings → Keyboard → View and Customise Shortcuts → Sound and Media → Play (or play/pause).
- Windows: Microsoft PowerToys → Keyboard Manager → remap your key to "Play/Pause Media".
- macOS: use the ▶❙❙ key.

Good to know
- Your system sends media keys to the player used most recently: if another app (Spotify, VLC…) played after Firefox, the key goes there.
- KDE with Plasma Browser Integration: turn off its "Media Controls" option, otherwise Plasma can send the key to Plasma Integration's own player, which controls a single tab.
- Players built purely on Web Audio (some games, synths) can't be paused.

Privacy: no data collected, nothing leaves your browser. Open source (MIT): https://github.com/cybWasHere/pause-key