On a Mac you add live captions to a live show by running a captioning app that listens to your audio, transcribes it locally, and outputs the text as a transparent overlay your streaming software (Ecamm Live, OBS, or Restream Studio) displays as a browser source. Because the captions are baked into your video before it leaves your Mac, they appear on every platform you stream to. The setup that reads best on screen gives each speaker their own colour, so viewers can tell who's talking at a glance instead of staring at one grey wall of text.
Why put captions on a live show at all?
Two reasons, and neither is the one people expect.
The obvious one is accessibility — a chunk of your audience watches with the sound off, or needs the text to follow along. That alone is worth it.
But the reason I built my own captioning tool is retention. When someone lands on your live stream mid-sentence, captions give them a way in. They can read the last line, catch the thread, and stay. No captions, and they bounce. On a live show, the first ten seconds decide everything.
The three ways to do it
1. Platform auto-captions. YouTube and a few others will auto-caption a live stream. They're free, they're fine, and you have zero control over how they look — usually a plain band of text pinned to the bottom, only on that one platform. If you multistream (and most serious creators do), they don't travel.
2. A browser or dictation hack. You can wire up the Mac's built-in dictation or a browser speech API and screen-capture it into a scene. It works until it doesn't, and styling it is a fight.
3. A dedicated captioning app that outputs an overlay. This is what I use and what I'd recommend if the show is part of how you make a living. The app does the transcription locally, and hands your streaming software a clean, transparent layer you can position, style, and — the part that matters — colour by speaker.
How the overlay approach works
The flow is the same whether you're in Ecamm Live, OBS, or Restream Studio:
- Run the captioning app. It listens to your microphone (or a specific audio input) and transcribes speech in real time on your Mac.
- Add the overlay as a source. The app serves the captions as a transparent web layer. In Ecamm you add it as a Web overlay; in OBS as a Browser source; in Restream Studio as a browser-based overlay. Point it at the app's local address and it appears over your video.
- Position and style it. Drag it where you want it, pick a size and a background treatment that stays readable over your scene.
- Go live. The captions track the conversation as it happens.
That's it. No cloud round-trip, no per-minute captioning fees, and it looks like part of the show rather than a bolt-on.
The one thing most caption tools miss: who's talking
Here's the gap that made me build Live Show Captions. Nearly every captioning option gives you a single stream of grey text. The moment you have a guest — an interview, a panel, a co-host — that text becomes a blur. Viewers can read the words but can't tell who said them.
The fix is a colour per speaker. Host in one colour, guest in another. Suddenly the caption track reads like a transcript of a conversation instead of a monologue. It's a small thing that changes how professional the whole stream feels.
The version I built goes one step further: you record a few seconds of each speaker once, the app builds a voice print, and from then on it recognises who's talking and switches the colour, name and side of the screen on its own, mid-conversation. No hotkeys, no clicking between speakers, no second pair of hands in the studio.
What to look for in a captioning app
If you're choosing a tool, these are the things that actually matter on a live show:
- Runs on your Mac, transcribes locally — lower latency, no per-minute costs, and your audio isn't shipped somewhere.
- Transparent overlay output — so it drops into Ecamm / OBS / Restream as a normal source.
- Per-speaker colour — the readability win above.
- A few clean styles — you want it to match your look, not fight it.
- Native, not a browser tab you babysit — one less thing to break mid-stream.
Frequently asked
Do I need a fast internet connection for live captions?
If the app transcribes locally on your Mac, no — the captioning runs on your machine, so your connection only carries the stream itself.
Will captions work if I multistream to several platforms at once?
Yes. Because the captions are an overlay baked into your video before it leaves your computer, every platform you send to shows the same captions — you're not relying on each platform's own captioning.
Can I caption a guest as well as myself?
That's the whole point of colour-per-speaker captioning — the host and guests each get their own colour so viewers always know who's speaking. A good tool captures your guest's audio straight from Zoom, Ecamm or the browser, with no virtual-audio cabling.
Are live captions accurate enough to use on a real show?
Modern on-device transcription is very good with a decent microphone, but no live captioning is perfect — expect the odd miss on names and jargon. For a live audience following a conversation that's fine; if you need compliance-grade accuracy, that's a job for a human captioner.
Do live captions cost per minute?
Cloud captioning services usually charge by the minute or the month, per platform. An app that transcribes on your own Mac has no per-minute metering — you pay for the app, and the captioning itself is free to run for as long as you stream.
Captions used to be a nice-to-have. On a live show that's meant to build your authority, they're part of looking like you know what you're doing — and the per-speaker colour is what separates "I turned captions on" from "this looks like a proper broadcast."
If you want the version I built for my own shows — native macOS, transparent overlay for Ecamm, OBS and Restream, a colour for every speaker, free for 7 days:
Get Live Show Captions →