Accessibility in live events is not a checkbox exercise. For the 1.5 billion people globally who live with hearing loss, and for the even larger number who benefit from captions in noisy, multilingual, or cognitively demanding environments, live captions are the difference between full participation and exclusion.

For event production teams and AV professionals, building accessibility into the captioning infrastructure from the start is both an ethical obligation and, in many jurisdictions, a legal one. The Equality Act in the UK, the Americans with Disabilities Act in the US, and equivalent legislation across the EU place specific duties on event organisers in relation to communication access. The tools below are those best designed to meet that standard.

Quick Comparison: Accessible Live Event Captioning Tools

1. Caption First

Caption First is a specialist CART provider with a strong reputation in the disability access community. It operates on a purely human captioning model, using trained stenographers who produce captions in real time with no AI assistance, which means accuracy is determined entirely by the skill of the captioner rather than the quality of an ASR engine. Its captioners are trained to meet the accuracy, synchronicity, and completeness standards referenced in accessibility legislation, and the company has extensive experience working with event teams to ensure captions are integrated into the physical event environment, including screen placement, display visibility, and audience sightlines, as well as the technical workflow.

Best for: Events where the highest-accuracy human CART captioning is the primary requirement.

Pricing: Custom; contact for a quote. captionfirst.com

2. Verbit

Verbit combines AI-driven transcription with a network of professional captioners who review and correct output in real time. Its hybrid model uses ASR as a first pass, with human captioners monitoring and editing the transcript live, which means accuracy improves as the session progresses and the engine adapts to the speaker. Its platform is built around compliance, with specific features designed to support WCAG, ADA, and Section 508 requirements. Verbit is widely used in higher education and corporate events, where accessibility documentation is often required alongside live caption delivery.

Best for: Enterprise and education events with strict compliance requirements.

Pricing: Custom enterprise pricing; contact Verbit for a quote. verbit.ai

3. 3Play Media

3Play Media operates a hybrid model, combining platform-assisted human CART captioning with AI/ASR for speed and scale. Human captioners work within the platform to review and correct AI output in real time, which gives event teams a reliable accuracy floor without depending entirely on stenographic resource. Its approach to accessibility is systematic: alongside its live CART service, it provides detailed post-event captioning review and quality assurance, plus a library of resources on WCAG caption standards and ADA compliance documentation. For event teams that need to demonstrate accessibility compliance to clients, venues, or regulators, 3Play Media's compliance reporting tools are a practical asset.

Best for: Teams that need both live captioning and post-event compliance documentation.

Pricing: Subscription plus usage; contact for enterprise rates. 3playmedia.com

4. Line 21

Line 21 was built with accessibility as its founding purpose. Its name references Line 21 of the analogue television signal, the line where closed captions were historically encoded, and the platform reflects that heritage with a depth of captioning capability that goes well beyond basic transcription. It operates as a hybrid platform, supporting professional human captioners (both stenographers and respeakers), multiple AI/ASR engines, and fully hybrid workflows where human and AI output can be combined or switched depending on the session requirements. This flexibility makes it equally suited to high-stakes events where a human captioner is essential and to large-scale or multi-stream productions where AI captioning needs to run reliably without manual oversight.

For accessible live event captioning, Line 21's key strengths are its support for professional human captioners (who deliver the accuracy levels required for deaf and hard-of-hearing attendees), its AI Proofreader (which reduces errors in real time regardless of captioning method), and its multi-destination output. Captions reach audiences wherever they are: in the venue, on the live stream, or on a personal device via a browser link. For international events, live translation into 100+ languages extends the accessibility benefit beyond hearing access to language access.

Line 21 operates on a pay-as-you-go model, making it a practical choice for event teams that do not want to commit to a fixed monthly contract. Volume discounts are available for organisations running regular or high-volume events.

Best for: AV teams and event producers needing flexible, multi-output captioning with both human and AI options.

Pricing: PAYG; volume discounts available. line-21.com

5. Syncwords

Syncwords is a cloud-based live captioning and translation platform that supports AI-generated captions in 50+ languages. It runs on a fully AI/ASR workflow with no human CART component, using machine learning models to generate captions directly from the audio feed in real time. This makes it well suited to teams that need rapid, automated deployment across multiple streams rather than the precision-reviewed output of a human captioner. It integrates with common streaming and conferencing platforms and is built for teams that need fast deployment without complex technical setup. Syncwords is a practical choice for multilingual events where speed of integration matters and a full human CART workflow is not a requirement.

Best for: Multilingual events needing quick AI captioning deployment across streaming platforms.

Pricing: PAYG and subscription options available. syncwords.com

6. AI-Media (LEXI)

AI-Media's LEXI platform runs on a pure AI/ASR workflow, using its proprietary speech recognition engine to generate captions directly from the audio feed without a human captioner in the loop. This makes it best suited to high-volume or broadcast-scale deployments where automated reliability and low operational overhead matter more than the precision of a reviewed human transcript. LEXI's ASR captioning engine is designed with broadcast accessibility standards in mind, delivering low-latency captions that meet the timing and synchronicity requirements referenced in accessibility legislation. For event teams working within existing encoder infrastructure, LEXI provides a purpose-built option with a proven track record in high-volume, regulated broadcast environments where caption accuracy is actively monitored.

Best for: Broadcast-adjacent events requiring low-latency ASR at scale.

Pricing: Subscription and custom; contact AI-Media for rates. ai-media.tv

7. TransPerfect

TransPerfect's MediaLink division offers a full suite of live captioning and translation services, combining human interpreters, CART captioners, and AI-assisted workflows. It operates a hybrid model, drawing on a large global network of professional linguists alongside AI-assisted tools to manage output at scale, which means it can handle both the accuracy demands of human CART and the throughput requirements of multilingual AI captioning within the same production. With that depth of resource, TransPerfect is suited to large-scale international events where multiple languages and accessibility formats need to be handled simultaneously and where enterprise-level support is expected.

Best for: Large international events requiring multilingual CART and translation at scale.

Pricing: Custom enterprise; contact TransPerfect for a quote. transperfect.com

Which Tool Is Right for Your Event?

The right choice depends on the scale of your event, your budget, and the level of accuracy your audience requires.

For AV teams and event producers who want flexible pricing and multi-output captioning without committing to a long-term contract, Line 21 is the most practical starting point. Its PAYG model, combined with support for both human captioners and AI engines across multiple destinations, makes it well suited to both one-off productions and recurring event programmes.

If you are planning an accessible live event and want to discuss your captioning requirements with a specialist team, get in touch with Line 21 to find out how they can support your production.

Citations and Further Reading

• World Health Organisation. (2023). World report on hearing. who.int
• UK Government. Equality Act 2010. legislation.gov.uk
• US Department of Justice. Americans with Disabilities Act. ada.gov
• W3C Web Accessibility Initiative. Captions/Subtitles (Web Accessibility Perspectives). w3.org
• Line 21. Platform overview and documentation. line-21.com / know.line-21.com/docs