Local Live Captions

Local Live Captions puts a caption panel over whatever is playing in a tab, the way Chrome's Live Caption does — except the speech recognition runs on your own machine, inside Firefox.

• Captions appear on their own as soon as a tab starts playing audio • Everything is local: after a one-time 27 MB model download the add-on works offline, and your audio is never uploaded • Works with ordinary video and audio players, with sites that play through the Web Audio API, and with radio and news players that other capture methods only hear as silence • Light on the CPU: the default Moonshine model updates the caption line in about a third of a second • Drag the panel anywhere, resize it, change the text size, pick dark or light • Optional, off by default: keep a transcript of each tab and save it as a text file • Whisper models for other languages, including translation into English; WebGPU where your Firefox supports it • A microphone source for calls or anything Firefox cannot capture, and an optional OpenAI-compatible transcription server • "Use recommended settings" restores the fastest, most dependable setup in one click

Keyboard shortcut: Ctrl+Shift+L (Cmd+Shift+L on macOS) toggles captions for the current tab.

Firefox asks you to grant site access before the add-on can read a page's audio.

Known limits: DRM-protected video cannot be captured, nor can a stream whose server refuses cross-origin access (microphone mode still works there); captions lag by about the length of the phrase being spoken.