Captioncast: Live Captions for Your Voice

Live captions for your voice in Chrome. On-device speech recognition, floating captions, and transcripts saved on your computer.

Turn your voice into live captions while you present in Chrome. Captioncast listens to your microphone and displays your speech as English captions. Use it for demos, lessons, walkthroughs, and screen sharing, so people can read along while you speak. Start captions, choose where they appear, and keep presenting. Speech recognition runs on your computer, and saved transcripts stay in your Chrome profile. WHAT YOU CAN DO • Caption your voice as you speak, with words updating during a sentence. • Show captions on the tab you are using or across supported tabs. • Open a floating caption window to position alongside your presentation. • Drag the on-page caption strip and adjust its text size. • Use a separate control window or Chrome's side panel. • Check the microphone level meter to see whether your voice is being picked up. • Choose your microphone and speech model. • Use keyboard shortcuts to control captions and show or hide the caption strip. • Copy saved transcripts or download them as TXT files. • Export SRT subtitles for sessions with saved timing information. • Delete individual saved sessions or clear your history. LOCAL SPEECH RECOGNITION Captioncast processes microphone audio on your device. It does not upload your microphone audio or transcripts to a speech recognition service, and no account is required. The selected speech model needs an initial download. Once that model is downloaded and cached, recognition can run offline. Choosing another model or clearing its cache may require another download. GET STARTED 1. Open Captioncast and press Start captions. 2. Allow microphone access when Chrome asks. 3. Let the speech model download on first use, then speak normally. 4. Choose your caption destination under Options, or open the floating window. 5. Press Stop when finished. Your transcript appears under Sessions. BEFORE YOU START • English speech, one speaker, using your microphone. Tab audio, system audio, and other call participants are not captured as separate audio sources. • Chrome 138 or newer is required. • Keep the Captioncast control window or side panel open while captions are running. • Page overlays work on supported websites, not Chrome settings pages, the Chrome Web Store, or other protected browser pages. • During screen sharing, your audience sees captions only if the shared surface includes them. • Speech recognition can make mistakes. Review transcripts and exported subtitles before sharing them. • Saved history keeps up to 20 sessions and the newest 400 lines per session. Export transcripts you want to keep. Captions displayed on a website may be accessible to that website. Choose where you display captions accordingly. Support: contact@polarislabs.pk