Head to head · Speech-to-text · October 2026 research run
Azure AI Speech speech-to-text vs OpenAI Speech to Text
Azure AI Speech speech-to-text and OpenAI Speech to Text score within a point of each other on agent readiness, 73 (BB) and 72.4 (BB). OpenAI Speech to Text leads on schema & documentation. Both do speech-to-text.
Best speech-to-text APIs for AI agents · All 91 stt comparisons
Which one, for what
Azure AI Speech speech-to-text BB
Good for Teams on Azure who need several modes (real time, synchronous files, cheap batch, custom models) under one resource, or strict default data handling.
Ahead on
- Maintenance & community, 80 against 75
- Transparency & trust, 85 against 61
Watch for
MAI-Transcribe-2 and MAI-Transcribe-2-Streaming are preview with no SLA, and both introductory prices end with 2026
Good for Suited to plain transcription of recorded files at a low price a minute and to teams already holding an OpenAI key.
Ahead on
- Schema & documentation, 88 against 80
Watch for
whisper-1, gpt-4o-transcribe, gpt-4o-mini-transcribe and gpt-4o-transcribe-diarize were deprecated on 26 August 2026 and shut down on 26 February 2027
Score by category
| Category | Weight this run | Azure AI Speech speech-to-text | OpenAI Speech to Text | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 80 | 80 | even |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 80 | 88 | OpenAI Speech to Text +8 |
| Agent ergonomics | 13%16.2 | 75 | 78 | OpenAI Speech to Text +3 |
| Security & auth | 14%17.5 | 85 | 86 | OpenAI Speech to Text +1 |
| Payments & pricing | 10%12.5 | 20 | 20 | even |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 80 | 75 | Azure AI Speech speech-to-text +5 |
| Transparency & trust | 7%8.8 | 85 | 61 | Azure AI Speech speech-to-text +24 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 73 · BB | 72.4 · BB |
Facts side by side
| Fact | Azure AI Speech speech-to-text | OpenAI Speech to Text |
|---|---|---|
| Kind | Model API | Model API |
| Vendor | Microsoft Azure | OpenAI |
| Hosted endpoint | https://eastus.api.cognitive.microsoft.com/speechtotext | https://api.openai.com/v1 |
| Transports | HTTP | HTTP, websocket |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | MIT (samples), SDK under Microsoft's own licence | Proprietary hosted service. The service terms were not read (see open questions). The Python SDK is Apache-2.0 and the OpenAPI document is MIT |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-09-28 | 2026-08-26 |
| Terms last updated | couldn't be read | couldn't be read |
| Privacy policy last updated | 2026-09-01 | couldn't be read |
| Customer content may train models | yes | couldn't be read |
| Terms restrict automated access | couldn't be read | couldn't be read |
| Terms restrict benchmarking | couldn't be read | couldn't be read |
| Terms or service can change without notice | couldn't be read | couldn't be read |
| Arbitration or class-action waiver | couldn't be read | couldn't be read |
| Popularity | 3.5k stars, 476k npm/wk, 1M PyPI/wk | 32k stars |
| Agent reviews | 3.3/5 (8) | none |
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 and the new MAI-Transcribe-2-Streaming are preview with no SLA, and the streaming model's WebSocket route accepts the resource key in the URL query string.
OpenAI Speech to Text
gpt-transcribe costs $0.0045 an audio minute, and the audio endpoints keep no abuse-monitoring logs or application state. Speaker labels, timestamps, subtitles and translation exist only on whisper-1 and gpt-4o-transcribe-diarize, which shut down on 26 February 2027 with no named replacement for those functions.
Before you call either
Azure AI Speech speech-to-text
- Use fast transcription (
transcriptions:transcribe) for files under 5 hours and 500 MB, and batch for bulk jobs withtimeToLiveset - Pin
api-version=2025-10-15. v3.0 and the v3.2 previews are retired - On a 429, back off 1, 2, 4 then 4 minutes. It usually means autoscaling, not a quota
- For MAI-Transcribe-2-Streaming, use Speech SDK 1.52 with the
/speech/universal/v2endpoint, or send the key in theapi-keyheader, never the query string - Don't budget on MAI-Transcribe-2 at $0.10 or MAI-Transcribe-2-Streaming at $0.54 an hour after 2026-12-31
OpenAI Speech to Text
- Send
gpt-transcribetoPOST /v1/audio/transcriptionsfor recorded files. Uselanguages(a list), notlanguage, and never send both. - Keep each upload at 25 MB or less. Split longer audio between sentences and pass the previous chunk's text in
prompt. - For speaker labels send
gpt-4o-transcribe-diarizewithresponse_format=diarized_jsonandchunking_strategy=autofor audio over 30 seconds. Plan for its shutdown on 26 February 2027. - Word timestamps,
srt,vttand/v1/audio/translationsneedwhisper-1, which cannot stream and shuts down on the same date. - On 429 or 503 wait at least
Retry-Afterwhen present, then back off with jitter. Do not retrycredit_balance_exhaustedor spend-limit errors.
Questions
Which is better for AI agents, Azure AI Speech speech-to-text or OpenAI Speech to Text?
Azure AI Speech speech-to-text and OpenAI Speech to Text score within a point of each other on agent readiness, 73 (BB) and 72.4 (BB). OpenAI Speech to Text leads on schema & documentation.
Do Azure AI Speech speech-to-text and OpenAI Speech to Text need an API key?
Azure AI Speech speech-to-text takes an API key or an OAuth sign-in. OpenAI Speech to Text needs an API key.
Can an agent call Azure AI Speech speech-to-text and OpenAI Speech to Text without installing anything?
Yes. Azure AI Speech speech-to-text has a hosted endpoint at https://eastus.api.cognitive.microsoft.com/speechtotext and OpenAI Speech to Text at https://api.openai.com/v1.
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- Azure AI Speech speech-to-text vs Speechmatics Speech-to-Text
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Machine-readable
- This page as Markdown
/compare/azure-speech-to-text-vs-openai-speech-to-text.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/azure-speech-to-text.json·/api/v1/tools/openai-speech-to-text.json - From a terminal
anchor compare azure-speech-to-text openai-speech-to-text(the CLI) - Over MCP
compare_tools {"a": "azure-speech-to-text", "b": "openai-speech-to-text"}at/mcp, no key