Can you recommend speech-to-text providers for real-time captioning with low latency and speaker diarization?

Yes — here are solid speech-to-text options for real-time captioning with low latency and speaker diarization. I’ll group them by what they’re best at.

Top options

1. Deepgram

• Best for: Low-latency live transcription, streaming apps
• Pros:
  • Very fast streaming STT
  • Good diarization support
  • Easy to integrate via API/WebSocket
  • Strong punctuation and formatting options
• Cons:
  • Diarization quality can vary with overlapping speech
• Good if: You need live captions with minimal delay

2. AssemblyAI

• Best for: High-quality transcription with useful post-processing
• Pros:
  • Speaker diarization available
  • Strong transcript quality
  • Easy API integration
  • Good for both async and streaming use cases
• Cons:
  • Streaming latency is good, but often not as aggressive as the fastest low-latency providers
• Good if: You want a balance of quality and developer experience

3. Google Cloud Speech-to-Text

• Best for: Enterprise-grade streaming recognition
• Pros:
  • Streaming support
  • Speaker diarization available in some configurations
  • Strong language support
  • Reliable infrastructure
• Cons:
  • Diarization in real-time can be less straightforward
  • Costs and configuration complexity can be higher
• Good if: You already use Google Cloud and need broad language coverage

4. AWS Transcribe

• Best for: AWS-native applications
• Pros:
  • Real-time streaming
  • Speaker diarization support
  • Integrates well with AWS ecosystem
• Cons:
  • Captions may require extra work for formatting/segmenting
  • Latency and diarization performance depend on setup
• Good if: Your stack is on AWS

5. Azure AI Speech

• Best for: Microsoft ecosystem / enterprise workflows
• Pros:
  • Streaming transcription
  • Speaker recognition / diarization capabilities
  • Solid enterprise support
• Cons:
  • Real-time diarization can be more complex to implement well
• Good if: You’re already using Azure services

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If latency is your top priority

Consider:

1. Deepgram
2. Google Cloud Speech-to-Text
3. AWS Transcribe

If speaker diarization quality matters more than pure speed:

1. AssemblyAI
2. Google Cloud Speech-to-Text
3. Azure AI Speech

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Important note on diarization in live captioning

True real-time speaker diarization is harder than basic transcription because the model has to:

• detect speech quickly,
• infer speaker identity,
• handle turn-taking,
• deal with overlaps.

In practice, many systems do:

• streaming transcription first
• then apply diarization with a short delay
• or refine speaker labels after the fact

So if you need captions on-screen with speaker labels, look for:

• streaming partial results
• timestamped word-level output
• speaker labels per segment
• low-end-to-end latency

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My practical recommendation

• Best overall for live captioning: Deepgram
• Best developer-friendly alternative: AssemblyAI
• Best if you’re on cloud hyperscalers: AWS Transcribe or Google Cloud Speech-to-Text

If you want, I can also give you:

1. a comparison table with latency, diarization, pricing, and languages, or
2. recommendations based on your stack, like WebRTC/live meetings, events, or broadcast captions.