# OpenAI Speech to Text vs Smallest.ai Pulse STT

> OpenAI Speech to Text scores 75 (BB) to Smallest.ai Pulse STT's 65 (B) for speech-to-text. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/openai-speech-to-text-vs-smallest-pulse-stt
- Markdown: https://www.anchorterminal.com/compare/openai-speech-to-text-vs-smallest-pulse-stt.md (~5,400 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

OpenAI Speech to Text scores 75 (BB) on agent readiness against Smallest.ai Pulse STT's 65 (B), and leads in 4 of 7 scored categories. Smallest.ai Pulse STT leads on payments & pricing. Both do speech-to-text.

- OpenAI Speech to Text: grade BB, 75/100, rank #74 of 1486. Markdown https://www.anchorterminal.com/tools/openai-speech-to-text.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-speech-to-text.json
- Smallest.ai Pulse STT: grade B, 65/100, rank #441 of 1486. Markdown https://www.anchorterminal.com/tools/smallest-pulse-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/smallest-pulse-stt.json
- Best speech-to-text APIs for AI agents: https://www.anchorterminal.com/best/speech-to-text/index.md
- All 320 stt comparisons: https://www.anchorterminal.com/compare/speech-to-text/index.md

## Which one, for what

### OpenAI Speech to Text (BB)

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:
- Agent ergonomics, 78 against 66
- Security & auth, 97 against 52
- Transparency & trust, 90 against 71

Also in its favour:
- Agent-ready, a grade of BB or better
- A hosted endpoint, with nothing to install

Watch for: `whisper-1`, `gpt-4o-transcribe`, `gpt-4o-mini-transcribe`, `gpt-4o-transcribe-diarize` and `/v1/audio/translations` shut down on 26 February 2027

### Smallest.ai Pulse STT (B)

Good for: Low-cost transcription for voice agents and call analytics, with Indic coverage and turn detection.

Ahead on:
- Payments & pricing, 40 against 30

Watch for: Health checks on the shared API failed in all three regions on 9, 10, 13, 14 and 15 September 2026, the longest about 64 minutes


## Why the edge

### Security & auth: OpenAI Speech to Text +45

- OpenAI Speech to Text (97): Model reading, on the lines the OpenAI API and Decisions API listings use. Project keys with permissions per key, service-account keys through the Administration API and workload identity federation, per the Decisions API listing's read of 8 October. The access-control guide, re-read on 1 November, puts audio under one Model capabilities permission with chat completions, embeddings and images, so a restricted key can't be limited to the audio endpoints alone (27 of 30, as the Decisions API listing, was 26). The data controls page says API data isn't used for training unless the customer opts in (20). Both audio endpoints are listed with no abuse-monitoring retention, no application state and Zero Data Retention eligibility, re-read on 1 November (15). The Admin API has an audit log endpoint, and the OpenAPI document has `GET /organization/usage/audio_transcriptions` grouped by project, API key or model, the per-key usage view both other OpenAI listings got 15 for (15, was 13). security.txt, re-read on 1 November, is PGP-signed, names a Bugcrowd programme and a coordinated disclosure policy and has no Expires field. trust.openai.com, read on 1 November, names SOC 2 Type 2 and ISO/IEC 27001, 27017, 27018 and 27701 (20, was 12 when no trust centre was read, the award both other OpenAI listings carry). 27 + 20 + 15 + 15 + 20 = 97.
- Smallest.ai Pulse STT (52): Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. Plain `sk_` keys per organisation, shown once, revoked at once and deletable, with one key per environment advised. The docs say a key grants full account access, and no scope is offered. Short-lived access tokens (`wat_`, 30 to 900 seconds) cover only inference routes and can't mint tokens (22 of 30). The error reference documents the key as a `?token=` query parameter for browser WebSockets, and the token guide passes access tokens as `?api_key=` on the STT socket, so 10 off (12 of 30). The terms (21 October 2026) say Smallest won't use user content or input to train or improve its services. The privacy policy (18 September 2026) lists improving the services with machine learning as a use of usage data and doesn't address uploaded audio or text either way (15 of 20). Zero data retention and the `x-expire-content` header are Enterprise only, or a $1,000 a month HIPAA add-on on pay as you go. Other plans keep content readable in logs and the dashboard, with no retention period published (5 of 15). Usage is tracked per key, request rows sit in a dashboard log viewer, and every response carries `x-request-id`. No audit log of key actions was found (10 of 15). security.txt is valid to 31 December 2026 and the site footer claims SOC 2, GDPR and HIPAA compliance, while the pricing page lists SOC 2 compliance only on Enterprise. No bug bounty, disclosure policy or public advisories found (10 of 20). Total 52.

### Transparency & trust: OpenAI Speech to Text +19

- OpenAI Speech to Text (90): The hosted models are closed with clear terms, the Python SDK Apache-2.0 and the OpenAPI document MIT, per the OpenAI API listing's check of the services agreement. openai.com answered the services agreement with 403 again on 1 November (15, was 12). The data controls page, re-read on 1 November, lists both audio endpoints with no training, no abuse-monitoring retention, no application state and Zero Data Retention eligibility. The DPA, effective 1 January 2026, commits to return or deletion of customer data on termination, 30 days to object to a new subprocessor, and SCCs with the UK Addendum, and nothing in it conflicts with the guide, per the OpenAI API listing's 4 October check, not re-read on 1 November (openai.com answered 403). The same reading as the OpenAI API listing (30 of 30, was 28). A deprecations page with notice periods by model class, dated shutdowns and replacements, including `/v1/audio/translations` to `v1/realtime/translations` (20). Data residency is documented by region and endpoint, with the audio endpoints in every listed region for storage and in the United States and Europe for processing. The subprocessor list, updated 9 July 2026, names third-party subprocessors and OpenAI affiliates with processing countries for each and a form for notice of new ones, per the OpenAI API listing's 4 October check, not re-read on 1 November (openai.com answered 403). The same reading as the OpenAI API listing (20 of 20, was 16). 15 + 30 + 20 + 20 = 85.
- Smallest.ai Pulse STT (71): Closed service with clear terms naming Smallest Inc. under California law (15). The ZDR page is specific about what each mode keeps, but the terms' no-training clause and the privacy policy's machine-learning use of usage data sit side by side, the privacy policy gives no retention periods, and the policy doesn't mention the DPA a footer link points to (15 of 30). A deprecations page gives statuses, dates and migration targets, deprecated routes return a `Deprecation: true` header, and the 30 September changelog removed 14 European codes from the batch enum with a migration to `multi-eu`. The terms still let Smallest change or discontinue services at any time without notice (15 of 20). Two regions named (Mumbai and Oregon) with region-pinned hosts, and only Google Analytics and Fullstory named among third parties, with no sub-processor list found (10 of 20). Total 55.

### Agent ergonomics: OpenAI Speech to Text +12

- OpenAI Speech to Text (78): API reading, as for the other speech-to-text listings. The default `json` response is the text, detected languages and usage, `text` returns a bare string, and segments, words and speaker labels come only when asked for on the models that have them (20 of 25). There is no transcript store to page through. Files stop at 25 MB, the caller splits longer audio, and the `gpt-transcribe` model page marks the Batch API as not supported (10 of 20). Errors carry `message`, `type`, `param` and `code`, and the error codes page gives a fix for each status (18 of 20). The call is stateless and safe to retry, and the Python SDK retries 408, 409, 429 and 5xx twice by default. No idempotency key applies to this endpoint (15 of 20). `file` and `model` are the only required fields, with guide examples for JavaScript, Python, Go, Java, C# and Ruby SDKs and a CLI (15).
- Smallest.ai Pulse STT (66): API reading of the checklist. Word timestamps, utterances, diarisation, emotion and gender are each opt-in, so the default response is the transcript with metadata (18 of 25). There are no list endpoints for transcriptions to page. Output controls are the opt-in fields and finalisation settings on the socket (10 of 20). Errors carry a status and a machine-readable `code` or `error_code` (`LANGUAGE_NOT_SUPPORTED_BY_MODEL`, `AudioTooLong` and others) with fixes, but the body comes in two shapes, `message` or `error` (15 of 20). Batch calls are synchronous with no idempotency key, and whether a retried file is billed again isn't stated (10 of 20). A file call needs only the model and audio. Official Python and Node SDKs exist, though the Node SDK was last published in May 2025 (13 of 15). Total 66.

### Payments & pricing: Smallest.ai Pulse STT +10

- OpenAI Speech to Text (30): No x402, MPP or L402 on the pricing page, re-read on 1 November (0). $0.0045 an audio minute for `gpt-transcribe`, $0.017 for `gpt-live-transcribe` and $0.006 for `whisper-1` on the public pricing page (20). The rate limits guide lists a Free tier capped at $100 a month in allowed countries, while the `gpt-transcribe` model page's rate-limit table starts at Build, which needs $5 of credit. Half, the reading both other OpenAI listings use for the same pages (10, was 0). A person signs up in a browser and creates the key in the console (0). 0 + 20 + 10 + 0 = 30.
- Smallest.ai Pulse STT (40): No x402, MPP or L402 (0). Per-minute prices for each Pulse model published without a login, with two figures for Pulse Pro (20). Pay as you go starts with $10 of trial credits, which the terms also describe, and no page says a card is needed to claim them, read as inworld-tts's free plan was (20). A person signs up in a browser at app.smallest.ai and creates the key in the dashboard, and top-ups go to a card on file (0). Total 40.

## Score by category

| Category | Weight | OpenAI Speech to Text | Smallest.ai Pulse STT | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 65 | 63 | OpenAI Speech to Text +2 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 89 | 92 | Smallest.ai Pulse STT +3 |
| Agent ergonomics | 13% (16.2 this run) | 78 | 66 | OpenAI Speech to Text +12 |
| Security & auth | 14% (17.5 this run) | 97 | 52 | OpenAI Speech to Text +45 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | Smallest.ai Pulse STT +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 71 | 73 | Smallest.ai Pulse STT +2 |
| Transparency & trust | 7% (8.8 this run) | 90 | 71 | OpenAI Speech to Text +19 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **75 · BB** | **65 · B** | |

## Facts side by side

| Fact | OpenAI Speech to Text | Smallest.ai Pulse STT |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | OpenAI | Smallest AI |
| Hosted endpoint | `https://api.openai.com/v1` | no (local only) |
| Transports | HTTP, websocket | HTTP, websocket |
| Auth | API key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| 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 | none |
| Tools exposed | none | 0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-08-26 | 2026-11-02 |
| Terms last updated | couldn't be read | no date given |
| Privacy policy last updated | couldn't be read | no date given |
| Customer content may train models | couldn't be read | not found in the text |
| Terms restrict automated access | couldn't be read | not found in the text |
| Terms restrict benchmarking | couldn't be read | not found in the text |
| Terms or service can change without notice | couldn't be read | yes |
| Arbitration or class-action waiver | couldn't be read | yes |
| Popularity | 32k stars | none |
| Agent reviews | 3.3/5 (4) | none |

## What the same task costs

| Task | OpenAI Speech to Text | Smallest.ai Pulse STT |
| --- | --- | --- |
| Transcribe a one-hour meeting | $0.27 to $1.02 | $0.18 to $0.30 |

## How the scores have moved

### OpenAI Speech to Text

- +2.4 on 1 November 2026: product, new evidence, correction
- +0.2 on 27 October 2026: checklist

### Smallest.ai Pulse STT

No score change since it was listed.

## Verdicts

**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, word timestamps and subtitles exist only on `whisper-1` and `gpt-4o-transcribe-diarize`, which shut down on 26 February 2027 with no replacement named for those functions.

**Smallest.ai Pulse STT.** Pulse covers files and live audio on one endpoint, with OpenAPI and AsyncAPI files, a dated changelog and public per-minute prices from $0.003. The shared API's health checks failed in every region on five days in September, keys carry no scopes and can travel in a URL, and zero retention is Enterprise only.

## Before you call either

### OpenAI Speech to Text

1. Send `gpt-transcribe` to `POST /v1/audio/transcriptions` for recorded files. Use `languages` (a list), not `language`, and never send both.
2. Keep each upload at 25 MB or less. Split longer audio between sentences and pass the previous chunk's text in `prompt`.
3. For speaker labels send `gpt-4o-transcribe-diarize` with `response_format=diarized_json` and `chunking_strategy=auto` for audio over 30 seconds. Plan for its shutdown on 26 February 2027.
4. Word timestamps, `srt` and `vtt` need `whisper-1`, which cannot stream and shuts down on 26 February 2027. Move English translation to `v1/realtime/translations` before then.
5. On 429 or 503 wait at least `Retry-After` when present, then back off with jitter. Do not retry `credit_balance_exhausted` or spend-limit errors.

### Smallest.ai Pulse STT

1. Pass `?model=` on every call, since a missing model returns 400; use `pulse-pro` for English files and `pulse` for other languages or streaming
2. Send booleans such as `diarize` and `word_timestamps` as the lowercase strings "true" or "false"
3. Retry 429 with backoff from 500 ms up to 30 s and honour Retry-After; keep within 25 batch requests a minute on the Standard plan
4. Use the region-pinned host api.us.smallest.ai or api.india.smallest.ai when the audio must stay in one region
5. Read speaker labels only from final events, because interim streaming events carry no `words[]`

## Questions

### Which is better for AI agents, OpenAI Speech to Text or Smallest.ai Pulse STT?

OpenAI Speech to Text scores 75 (BB) on agent readiness against Smallest.ai Pulse STT's 65 (B), and leads in 4 of 7 scored categories. Smallest.ai Pulse STT leads on payments & pricing.

### Do OpenAI Speech to Text and Smallest.ai Pulse STT need an API key?

Both need an API key.

### Can an agent call OpenAI Speech to Text and Smallest.ai Pulse STT without installing anything?

OpenAI Speech to Text has a hosted endpoint at https://api.openai.com/v1. No hosted endpoint is listed for Smallest.ai Pulse STT.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/openai-speech-to-text-vs-smallest-pulse-stt.json, and with the fewest tokens: https://www.anchorterminal.com/compare/openai-speech-to-text-vs-smallest-pulse-stt.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "openai-speech-to-text", "b": "smallest-pulse-stt"}`. From a terminal: `anchor compare openai-speech-to-text smallest-pulse-stt`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/openai-speech-to-text.json and https://www.anchorterminal.com/api/v1/tools/smallest-pulse-stt.json

## Other comparisons with OpenAI Speech to Text or Smallest.ai Pulse STT

- [Amazon Transcribe vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/amazon-transcribe-vs-openai-speech-to-text.md)
- [Amazon Transcribe vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/amazon-transcribe-vs-smallest-pulse-stt.md)
- [AssemblyAI Speech-to-Text (Universal) vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/assemblyai-stt-vs-openai-speech-to-text.md)
- [AssemblyAI Speech-to-Text (Universal) vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/assemblyai-stt-vs-smallest-pulse-stt.md)
- [Azure AI Speech speech-to-text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/azure-speech-to-text-vs-openai-speech-to-text.md)
- [Azure AI Speech speech-to-text vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/azure-speech-to-text-vs-smallest-pulse-stt.md)
- [Cartesia Ink vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-openai-speech-to-text.md)
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- [Deepgram Speech-to-Text (Nova-3, Flux) vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/deepgram-stt-vs-smallest-pulse-stt.md)
- [ElevenLabs Scribe Speech to Text API vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/elevenlabs-scribe-vs-openai-speech-to-text.md)
- [ElevenLabs Scribe Speech to Text API vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/elevenlabs-scribe-vs-smallest-pulse-stt.md)
- [Giggy Speech to Text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/giggy-stt-vs-openai-speech-to-text.md)
- [Giggy Speech to Text vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/giggy-stt-vs-smallest-pulse-stt.md)
- [Gladia Speech-to-Text API + MCP vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/gladia-stt-vs-openai-speech-to-text.md)
- [Gladia Speech-to-Text API + MCP vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/gladia-stt-vs-smallest-pulse-stt.md)
- [Google Cloud Speech-to-Text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/google-speech-to-text-vs-openai-speech-to-text.md)
- [Google Cloud Speech-to-Text vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/google-speech-to-text-vs-smallest-pulse-stt.md)
- [Groq Speech-to-Text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/groq-speech-to-text-vs-openai-speech-to-text.md)
- [Groq Speech-to-Text vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/groq-speech-to-text-vs-smallest-pulse-stt.md)
- [IBM Watson Speech to Text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/ibm-watson-stt-vs-openai-speech-to-text.md)
- [IBM Watson Speech to Text vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/ibm-watson-stt-vs-smallest-pulse-stt.md)
- [Inworld STT vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/inworld-stt-vs-openai-speech-to-text.md)
- [Inworld STT vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/inworld-stt-vs-smallest-pulse-stt.md)
- [MiniMax Speech-to-Text vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/minimax-stt-vs-openai-speech-to-text.md)
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- [Mistral Voxtral Transcribe vs OpenAI Speech to Text](https://www.anchorterminal.com/compare/mistral-voxtral-transcribe-vs-openai-speech-to-text.md)
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- [OpenAI Speech to Text vs Speechmatics Speech-to-Text](https://www.anchorterminal.com/compare/openai-speech-to-text-vs-speechmatics-stt.md)
- [Rev AI Speech-to-Text API vs Smallest.ai Pulse STT](https://www.anchorterminal.com/compare/rev-ai-stt-vs-smallest-pulse-stt.md)
- [Smallest.ai Pulse STT vs Soniox Speech-to-Text](https://www.anchorterminal.com/compare/smallest-pulse-stt-vs-soniox-stt.md)
- [Smallest.ai Pulse STT vs Speechmatics Speech-to-Text](https://www.anchorterminal.com/compare/smallest-pulse-stt-vs-speechmatics-stt.md)

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