Caption what your computer plays

Caption computer audio on Mac and Windows

A microphone hears the room. System audio hears the call. Which one you need, how to set it up, and what usually goes wrong.

3 audio sources 3 min read Published October 2026

If your meeting, webinar, or video plays through your own computer, the cleanest way to caption it isn't to hold a microphone near your speakers. It's to capture the audio directly, before it reaches them. The idea is simple and the setup is fiddly, which is why people search for it constantly. There are three audio sources, and picking the right one solves most captioning problems before they start. Here's how each works on Mac and Windows, and a troubleshooting list for when you hear audio but see no captions.

Three audio sources, three use cases

Source	What it captures	Best for	Watch out for
Microphone	Your voice and room sound	In-person conversations, your own speech	Picks up echo and noise if you use speakers
Tab audio (browser)	Audio from one browser tab	Web meetings, webinars, YouTube, streams	Needs a Chrome-based browser; you choose the tab and share its audio
System audio (desktop app)	Everything your computer plays	Desktop apps like Zoom, Teams, WhatsApp Desktop	Includes notification sounds; mute what you don't want captioned

Operating-system rules differ. As of this writing, tab audio capture is the easiest route in a Chrome-based browser on both macOS and Windows, while capturing all system audio typically uses a desktop app built for it. Check each tool's current instructions.

Setup in four steps

Choose the source

Web meeting or video in a browser: tab audio. Desktop app on your computer: system audio. In person: microphone.

Start the captioning tool first

Open it, pick the audio source and your languages, and grant the permissions it asks for.

Start or join the meeting

For tab audio, select the meeting tab and make sure "share tab audio" is on. For system audio, play a few seconds of sound to confirm captions appear.

Check levels and adjust

Turn the meeting volume up enough for clear audio. Use headphones if you also use the microphone, to avoid feedback.

Troubleshooting: hearing audio, seeing no captions

Tab audio not shared. In the browser's sharing prompt, make sure the audio option is ticked.

Wrong tab or window selected. Share the tab that actually plays the meeting.

Permissions blocked. On macOS, check Screen Recording and Microphone permissions in System Settings; on Windows, check microphone privacy settings.

Output device mismatch. If sound plays through a different device than the tool is capturing, switch them to match.

Muted or very quiet source. Captions follow what's actually playing.

Echo from speakers into the mic. Use headphones.

For platform-specific captions without host permission, see live captions without host permission, and for built-ins, turning on live captions on Mac and Windows.

How Unicaption handles it

Microphone, system audio, or tab audio, your choice per session
Browser, macOS and Windows desktop apps, and a Chrome extension
Live captions with side-by-side translation in 60+ languages and automatic language detection
Works beside any platform (Zoom, Teams, Google Meet, Webex, WhatsApp Desktop, FaceTime on Mac), with nothing joining the call
Nothing stored: end-to-end encrypted, audio never saved, transcripts deleted when the session ends, never used to train models

Try it free: 30 minutes every week, no credit card.

Frequently asked

How do I get live captions of my computer's audio?

Use a captioning tool that captures system or tab audio instead of the microphone. In a Chrome-based browser you can share a single tab's audio; desktop apps on macOS and Windows can capture system audio. Unicaption supports microphone, system, and tab audio and shows live captions with side-by-side translation in 60+ languages.

Why are my captions empty even though I can hear the audio?

Usually the audio source isn't being shared. For tab capture, make sure the share-audio option is ticked and you picked the right tab. On macOS check Screen Recording and Microphone permissions. Also confirm the output device matches the one the tool captures.

Can I caption a Zoom or Teams meeting without a bot?

Yes. Capturing the meeting's audio on your own computer means nothing joins the call. Unicaption does this with tab or system audio, so no participant appears and the host needs no setting.

Caption anything your computer plays

Mic, tab, or system audio. 30 free minutes every week.

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