How to Add Live Captions in vMix
vMix can show live captions through a Browser input. LiveSunday listens to your audio, writes the text, and gives you a transparent overlay URL to paste over your program mix.
Written by Victor S.
Last updated September 4, 2026
vMix will switch your cameras, play your slides, and send the program to YouTube. It will not listen to the person on the mic and write captions as they talk.
That gap shows up the first time someone asks for captions on the livestream. Hard of hearing people in the room. Spanish speakers who could follow a sermon if the words were on screen. Viewers who watch with the sound off. You already have a production switcher. You need the text.
The hack a lot of teams try is capturing a phone or a Chrome tab into vMix. It works in rehearsal. Then a Windows notification covers the words, or someone closes the tab during the second song. If the window isn't 16:9, the text ends up huge in the corner of a 1080p program. Typing captions live is worse. Nobody keeps up with a sermon.
LiveSunday is the piece that actually writes the captions.
What LiveSunday is, and why it belongs in this setup
LiveSunday is software for live captions and translation at services and events. You send it a clean audio feed from the sound board, the same kind of tap you'd use for a recording or a stream encoder. It transcribes the speech as it happens. If you need another language, it translates that text too.
People in the seats can scan a QR code and read on their phones. No app to install. That's the right path when you want to keep the stage screens clean.
The other output is what vMix cares about. LiveSunday publishes an overlay URL, a web page with no background, only the caption text. You load that page as a Browser input and stack it over cameras and slides. Captions sit on the picture the way a lower third does, except the words update as the speaker talks.
That's why you'd use it here. vMix already has Browser inputs. No plugin, and no separate caption encoder. One URL per language, sized to your canvas, sitting in the mix like any other overlay.
What you need
A LiveSunday account. In the dashboard, open Captions, create a caption link, pick the language and the look of the text, then copy the overlay URL. It looks like https://livesunday.ai/overlay/abc123.
vMix on the machine that switches the service, or on a graphics PC that can feed that mix.
Audio already reaching LiveSunday. The overlay stays empty until you click Start stream in the dashboard. If you skip that, vMix looks broken. The input is fine. Nothing has been published yet.
Add the overlay in vMix
Copy the overlay URL
Open Captions in LiveSunday, open the link you saved, and copy the overlay URL.
Add a Browser input
In vMix, click Add Input, then Browser. Name it something you'll recognize at 8:50am, like LiveSunday Spanish.
Paste the URL and match the canvas
Set the URL to the overlay link. Set width and height to your output. Most rooms are 1920×1080.
If the Browser input is 1280×720 on a 1080p mix, the text looks oversized or gets clipped. Match the output, not whatever default vMix filled in.
Click OK.
Layer it over program
In MultiView, put the Browser input above cameras and slides. The page is transparent, so only caption text shows.
Start the LiveSunday stream
In the LiveSunday dashboard, click Start stream. Captions should show in the vMix preview within a few seconds. Do this before the first song, not after someone already asked where the captions went.
What actually breaks
The overlay stays blank when LiveSunday isn't streaming yet. Start the stream in the dashboard first. Wrong size is the other usual problem. Match width and height to program output.
If captions freeze, open the Browser input settings and refresh, or restart the LiveSunday stream.
Don't edit one URL mid-service to switch languages. Make a caption link per language and a Browser input per language. Send them to different screens or buses if you need English and Spanish at the same time.
Does this go out on the livestream?
Yes, if the Browser input is in the mix that feeds recording or RTMP. If you parked it on a preview that never hits program, YouTube won't see it. Same rule as a lower third.
You can keep captions off the house screens and let people use the QR code on their phones. Some rooms do both. Some keep the stage screens clean and only caption the stream.
If you stream from OBS instead of vMix, the same overlay URL goes in as a Browser Source. The idea is identical. Paste the page, match the canvas, put it on top.
FAQ
Does vMix need a plugin?
No. Browser input is built into vMix. Paste the overlay URL.
Can Spanish and English run at once?
Yes. Two caption links, two Browser inputs. Route them to the outputs that need them.
Do people in the room need an app?
No. The overlay is for the mix. Phone viewers scan a QR code and read in the browser.
LiveSunday is live caption and translation software for churches and events. Start at livesunday.ai.