CaptionCast
GitHub

Live captions, shared simply

One speaker.
Everyone follows.

Turn one microphone into live captions for every phone in the room—each in the language that helps them follow.

View on GitHub
Scroll to see it happen

From microphone to every screen

A room opens.
The distance disappears.

Scroll through the flow, or press play and watch CaptionCast bring everyone into the same conversation.

01 — Speaker

Open the room.

Choose a caption provider and open a space for your audience before you begin.

C CaptionCast Speaker
Ready

1Choose a caption provider

A Live translationTranslated captions and optional audio
W Free captionsBrowser speech recognition
Live roomAudience
0
EN 1日本語 1ES 1
CCaptionCast
Live translation

Choose your language

LIVE

皆さん、講演へようこそ。

Welcome everyone to the talk.
EN

Welcome everyone
to the talk.

ES

Bienvenidos
a todos.

1 / 5
  1. 01

    Open a room

    Choose how captions are created, then welcome your audience before the talk starts.

  2. 02

    Share one link

    Put the QR code on a slide or send the link. Nothing needs to be installed.

  3. 03

    Everyone chooses

    Each listener follows on their own screen, in their own language and text size.

  4. 04

    Speak naturally

    Partial captions appear immediately, then settle into accurate committed lines.

  5. 05

    Stay together

    Reconnection and local history help the conversation keep moving.

Made for rooms that want everyone in

Useful wherever words need to travel.

01

Presentations

Put the join code on your opening slide and give every seat a clearer view.

02

Classes

Help learners follow terminology, another language, or a difficult acoustic space.

03

International events

Let multilingual audiences choose the translation that works for them.

04

Hybrid and community talks

Support remote listeners, noisy venues, and people who read along to understand.

Small details, calmer sessions

Built to disappear into the moment.

Aa

Live as you speak

Growing partial text gives the audience words now; committed lines bring clarity after the pause.

文

A language for each listener

One shared room can serve multiple caption languages without splitting the audience.

↻

Ready for real networks

Automatic reconnection and careful backpressure keep temporary interruptions uneventful.

◌

Choose your engine

Use free browser captions or connect supported metered providers when accuracy or translation matters.

A±

Personal on every screen

Listeners control text size, theme, language, optional audio, and their local conversation history.

⌁

Nothing to install

A browser and one link are enough for the audience to join from a phone, tablet, or laptop.

Open by design

Your room.
Your infrastructure.

CaptionCast is open source and designed to self-host. Provider credentials stay on the relay, while committed caption history stays in each listener’s browser.

Explore the code Self-host CaptionCast
SpeakerMicrophone
CloudflareCaption relayKeys stay here
ENViewer
日本語Viewer
ESViewer

Make every word easier to reach.

Open source. Built for the browser. Ready for your next room.

Get CaptionCast