The complete unit economics guide for AI voice bots, call center transcription, and meeting note agents. Compare latency, word error rates (WER), and volume discounts.
The industry standard for voice agents (Vapi, Retell, LiveKit). Delivers sub-250ms streaming latency over WebSockets, industry-lowest Word Error Rate on accented speech, and native speaker diarization.
Powered by Groq's custom LPU hardware. Transcribes audio at an astonishing 250x realtime speed. The absolute lowest-cost endpoint available for processing pre-recorded podcasts, voicemails, and audio files.
OpenAI's official managed transcription endpoint. Excellent translation capabilities across 98 languages, reliable punctuation, and built-in timestamp generation. Batch processing only.
Specialized for telephony and conversation intelligence. Provides automatic sentiment analysis, PII redaction, topic detection, and chapter generation alongside accurate transcripts.
| Provider & Model | Cost / Minute | Cost / Hour | 1,000 Hours Cost | Streaming Latency | Word Error Rate (WER) | Best For |
|---|---|---|---|---|---|---|
| Groq Whisper Large v3 | $0.0018 | $0.111 | $111 | Batch only (250x RT) | 7.2% | Massive batch audio archives |
| Deepgram Nova-3 | $0.0043 | $0.258 | $258 | ~220ms | 6.84% | Real-time voice bots, LiveKit |
| Deepgram Nova-2 | $0.0043 | $0.258 | $258 | ~260ms | 7.80% | Legacy telephony pipelines |
| OpenAI Whisper Large v3 | $0.0060 | $0.360 | $360 | Batch only | 7.4% | Multilingual translation |
| AssemblyAI Best | $0.0065 | $0.390 | $390 | ~350ms | 7.1% | PII redaction, call analytics |
| Gladia Audio Intelligence | $0.0090 | $0.540 | $540 | ~300ms | 7.5% | Multi-speaker overlap meetings |
| Google Cloud Speech-to-Text | $0.0160 | $0.960 | $960 | ~400ms | 8.4% | Google Workspace integrations |
For conversational AI voice bots (e.g. AI receptionists or support agents), Time to First Transcript Token (TTFT) is everything. If your user says "hello" and transcription takes 800ms, your entire conversational turn will feel sluggish and unnatural. In this scenario, Deepgram Nova-3 via streaming WebSockets is the only viable choice under $0.005/min.
Conversely, if your workload is transcribing recorded customer service calls or user voicemails after the fact, streaming low-latency is completely irrelevant. Routing recorded files to Groq Whisper Large v3 at $0.0018/min reduces your transcription expenses by nearly 60% with zero quality degradation.