Captioning, Accessibility + Compliance

Deliver accessible, compliant captioning powered by Voice AI

Generate accurate real-time and post-production captions for live events, broadcasts, and video content to meet ADA, WCAG, and FCC compliance standards.

Get started

increase in free-to-paid conversion rate

See case study

“We needed a provider that could scale with us — offering unlimited concurrent streams, fair pricing, and responsive support.”

80%

increase in customer satisfaction

See case study

“Assembly has saved us countless hours managing models, and provided exceptional accuracy.”

increase in free-to-paid conversion rate

See case study

“We needed a provider that could scale with us — offering unlimited concurrent streams, fair pricing, and responsive support.”

80%

increase in customer satisfaction

See case study

“Assembly has saved us countless hours managing models, and provided exceptional accuracy.”

Capabilities

Built for every captioning workflow

Generate accessible, compliant captions and subtitles across live and recorded content.

Word-level timestamps for precise synchronization

Sync captions perfectly with audio for broadcast compliance

Export to SRT/VTT out of the box

Caption recorded content with frame-level accuracy

Real-time captioning with sub-300ms latency

Deliver sub-300ms latency for live captioning

Stream low-latency captions for events and webinars

Keep pace with speakers in real time

Price-performance and scalability that grows with you

Pay as you go with no minimum commitment

Unlock volume discounts as you scale

Count on 99.9% uptime SLA at a fraction of legacy pricing

Platform

One API, every captioning workflow

Accuracy that meets accessibility standards, with word-level timestamps for precise caption synchronization.

Speech-to-Text API

Highest-accuracy batch transcription for post-production subtitle generation, video captioning, and accessibility compliance workflows.

See the models Try for free

Streaming Speech-to-Text API

Sub-300ms real-time accuracy for live event captioning, broadcast accessibility, and real-time subtitle generation with word-level timestamps.

See the models Try for free

Benchmarks

Lowest error rate in the industry

The crucial details captured more accurately than ever — powering reliable downstream workflows.

	AssemblyAI Universal-3 Pro	Speechmatics Enhanced Model	Deepgram Nova-3	AWS Transcribe	OpenAI GPT-4o Transcribe
MER	7.5%	17.33%	18.69%	20.76%	12.29%
WER	4.5%	6.1%	6.66%	12.9%	5.34%

Playground

We're not playing around, but you can

Put our Voice AI models to the test in our no-code playground.

Try it now