# How to Caption Computer Audio on Mac and Windows (System Audio)

> To caption audio your computer is playing, use a tool that captures system or tab audio instead of the microphone. In a Chrome-based browser, tab audio capture lets you caption a single tab such as a Zoom web, Meet, or YouTube tab. Desktop apps for macOS and Windows can capture system audio. Unicaption supports microphone, system, and tab audio, with live captions and side-by-side translation in 60+ languages and nothing stored.

Published 2026-10-05 · The Unicaption Team · Human-readable version: https://unicaption.com/blog/caption-system-audio-mac-windows.html

## 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

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

**2. Start the captioning tool first**
Open it, pick the audio source and your languages, and grant the permissions it asks for.

**3. 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.

**4. 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](/blog/live-captions-without-host-permission.html), and for built-ins, [turning on live captions on Mac and Windows](/blog/turn-on-live-captions-mac-windows.html).

## 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.

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*[Unicaption](https://unicaption.com) is a real-time AI captioning and translation copilot for human interpreters — live captions and translation in 60+ languages, end-to-end encrypted, nothing stored. 30 free minutes every week, no credit card required.*