Curiosity · AI Model

Deepgram Nova-3

Deepgram Nova-3 is Deepgram's third-generation flagship ASR model, purpose-built for real-time streaming transcription. It delivers sub-300 ms end-to-end latency, built-in diarisation, and keyterm prompting that boosts accuracy on domain jargon — the reason it anchors many voice-agent and contact-centre stacks.

Model specs

Vendor
Deepgram
Family
Nova
Released
2025-02
Context window
1 tokens
Modalities
text, audio
Input price
n/a
Output price
n/a
Pricing as of
2026-04-20

Strengths

  • Sub-300 ms real-time latency
  • Built-in diarisation and keyterm prompting
  • Strong accented-English WER versus Whisper-class models
  • Self-serve API plus dedicated contact-centre connectors

Limitations

  • Fewer languages than Whisper large-v3 (though expanding)
  • Closed API only — no self-hostable weights
  • Per-minute pricing can add up on long archives
  • Nova-3 tuning favours English and major EU languages

Use cases

  • Voice agents and realtime AI phone calls
  • Live captioning and conference subtitles
  • Contact-centre analytics and QA
  • Meeting-notes pipelines with diarisation

Benchmarks

BenchmarkScoreAs of
English WER (Nova-3)≈6.8%2025
Real-time latency p95<300 ms2025

Frequently asked questions

What is Deepgram Nova-3?

Nova-3 is Deepgram's third-generation speech-to-text model, designed for streaming real-time transcription. It emphasises low latency, built-in diarisation, and keyterm prompting to boost accuracy on domain-specific vocabulary.

How is Nova-3 different from Whisper?

Whisper is open-weight and great for batch transcription, but was not built for streaming. Nova-3 is closed-API-only but purpose-built for real-time voice agents, contact centres, and live captioning, with sub-300 ms end-to-end latency.

What is keyterm prompting?

Keyterm prompting lets you pass a list of domain-specific terms (product names, medical terminology, people names) with each request. The model biases decoding toward these terms, improving WER on jargon-heavy audio.

How is Deepgram priced?

Deepgram bills per minute of audio processed, with separate rates for streaming versus batch. Enterprise contracts offer volume discounts, HIPAA, and on-prem options.

Sources

  1. Deepgram — Nova-3 announcement — accessed 2026-04-20
  2. Deepgram — API docs — accessed 2026-04-20