Line 21 Live Captions

Intro

Line 21 Live Captions is a live captions platform that combines human captioners and AI capabilities. Public pages list both manual captioning and automated speech recognition (ASR) as available options, and the product includes tools intended to support live streams and post-production workflows. The company publishes a privacy policy that states privacy and data security are a top priority. Pricing information on the public site indicates pay-as-you-go billing with rates advertised from $0.04 per minute and an example rate shown as "Caption Minutes $3 / hour."

Key Features

• Manual Captioning: human captioners for live or recorded content.
• ASR (automatic speech recognition): automated caption generation.
• RTMP streaming support: integration point for live video feeds.
• HLS streaming support: playback-oriented streaming support.
• AI Translations: machine translation of captions.
• AI Proofreader: automated proofreading of generated captions.
• AI Context Builder: tools to provide contextual signals or metadata to the captioning process.
• Embeddable player: a player component to present captions with video.

Who this is for

Line 21 is positioned for clients who require captions for events and for agencies that want to use the technology with their own clients. The public pricing model is pay-as-you-go with no subscription plans listed, which is explicitly stated on the pricing page. Available documentation and pages do not list explicit caption accuracy metrics, a complete language matrix, service-level agreements, detailed API documentation, manual caption turnaround times, billing currency options, or customer case studies, so prospective buyers should request those details directly if they need them before procurement.