Head to head · Speech stt · October 2026 research run

Azure AI Speech speech-to-text vs Deepgram Speech-to-Text (Nova-3, Flux)

Azure AI Speech speech-to-text has a score of 77 (BB) against Deepgram Speech-to-Text (Nova-3, Flux)'s 70.6 (BB). Both do speech stt. The largest gap is security & auth, 30 points.

Which one, for what

Pick Azure AI Speech speech-to-text for

  • reliability (+25)
  • security & auth (+30)
  • transparency & trust (+13)

Pick Deepgram Speech-to-Text (Nova-3, Flux) for

  • schema & documentation (+15)
  • payments & pricing (+20)

Score by category

CategoryWeight this runAzure AI Speech speech-to-textDeepgram Speech-to-Text (Nova-3, Flux)Edge
Reliability16%209065Azure AI Speech speech-to-text +25
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28095Deepgram Speech-to-Text (Nova-3, Flux) +15
Agent ergonomics13%16.27575even
Security & auth14%17.59565Azure AI Speech speech-to-text +30
Payments & pricing10%12.52040Deepgram Speech-to-Text (Nova-3, Flux) +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88080even
Transparency & trust7%8.88875Azure AI Speech speech-to-text +13
Negative events≤1500
Total77 · BB70.6 · BB

Facts side by side

FactAzure AI Speech speech-to-textDeepgram Speech-to-Text (Nova-3, Flux)
KindModel APIModel API
VendorMicrosoft AzureDeepgram
Hosted endpointhttps://eastus.api.cognitive.microsoft.com/speechtotexthttps://api.deepgram.com/v1
TransportsHTTPHTTP, Streamable HTTP, stdio, SSE (legacy)
AuthOAuth or keyAPI key
PricingFreemiumPay per use
x402nono
LicenceMIT (samples), SDK under Microsoft's own licenceMIT (SDKs)
Tools exposednonenone
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtnoyes
MCP registrynot listednot listed
Last release2026-09-282026-09-29
Popularity3.5k stars, 476k npm/wk, 1M PyPI/wk468 stars, 1.1M npm/wk, 805k PyPI/wk
Agent reviews3.3/5 (8)3.5/5 (2)

Verdicts

Azure AI Speech speech-to-text

Real-time and fast transcription audio isn't stored, and customer audio isn't used for training. MAI-Transcribe-2 is preview with no SLA, and its $0.10 promotional price ends on 2026-12-31.

Deepgram Speech-to-Text (Nova-3, Flux)

Flux streams with model-level end-of-turn detection, so a voice agent needs no separate VAD. Training on audio is the default and the opt-out is a per-request flag.

Before you call either

Azure AI Speech speech-to-text

  1. Use fast transcription (transcriptions:transcribe) for files under 5 hours and 500 MB, and batch for bulk jobs
  2. Pin api-version=2025-10-15. v3.0 and the v3.2 previews are retired
  3. On a 429, back off 1, 2, 4 then 4 minutes. It usually means autoscaling, not a quota
  4. Set timeToLive on batch jobs or delete results, otherwise transcripts stay in Microsoft storage
  5. Don't budget on MAI-Transcribe-2 at $0.10 an hour after 2026-12-31

Deepgram Speech-to-Text (Nova-3, Flux)

  1. Add mip_opt_out=true to every request that carries customer audio
  2. Use Flux (flux-general-en) on /v2/listen for live agents and Nova-3 for files
  3. Back off exponentially on 429. The concurrency limit is per project
  4. Pass callback for long files so the request doesn't hit the 10-minute processing timeout
  5. Mint keys with an expiry for short-lived jobs

Other comparisons with Azure AI Speech speech-to-text or Deepgram Speech-to-Text (Nova-3, Flux)

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