Overview

Start here — quick links, highlights, and the best paths through Line 21 documentation.

Essentials

The core concepts you’ll use in almost every setup: how captions are created, how languages work, and how you deliver them to viewers.

Create an account, set up your organisation, and learn the basics.

Human, ASR, and playback — when to use each and what to expect.

How language channels work (and how to add translations).

Where captions go: browser, overlay, streaming, and text destinations.

Deep dives for production workflows, integrations, and teams that want more control.

Understand audio/video inputs and how they affect caption quality.

Add translations, proofreading, and other assistive capabilities.

Monitor live events, coordinate with the team, and review assets after.

Programmatic integrations for caption production and retrieval.

Operational how‑tos for running a live event in the web app.

Data retention, AI training, third-party processors, and client options.

Quick answers to the questions we hear most often.

For any questions, feedback, or support, please contact us here.