IBM watsonx Speech to Text

Best for: Prototypes and side projects - free to start, no sales call; Regulated or enterprise workloads - compliance attestations and an enterprise plan; Teams needing broad API coverage out of the box

Pricing model

Usage-based [2]github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Plus Plan: Tiered pricing: $0.02 (USD) per minute for 1-999,999 minutes monthly; $0.01 (USD) per minute for 1M+ minutes. No base subscription fee mentioned.”cloud.ibm.com/docs/speech-to-text“For the Plus plan, pricing starts at $0.02 USD per minute for 1 - 999,999 minutes used, and $0.01 USD per minute for 1,000,000+ minutes.”

Published pricing

✓ Yes

Free tier

✓ Yes [3]github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Lite Plan: 500 minutes per month at no cost. No customization access. Services deleted after 30 days of inactivity.”cloud.ibm.com/docs/speech-to-text“The Lite plan is free and provides 500 minutes of speech recognition per month at no cost.”

Free tier details

Lite plan: 500 minutes per month at no cost (recurring monthly allowance). No customization access on Lite; service deleted after 30 days of inactivity. Plus plan (paid, no base fee): first 1–999,999 minutes at $0.02 USD/minute, 1,000,000+ minutes at $0.01 USD/minute. Premium plan (requires sales contact) includes first 150,000 minutes/month at no charge; pricing beyond that is not publicly disclosed.

Self-serve signup

✓ Yes [4]cloud.ibm.com/catalog/services/speech-to-text“Speech to Text - IBM Cloud catalog listing allows self-serve signup for Lite and Plus plans directly through IBM Cloud.”

Requires sales call

✗ No

Enterprise plan

✓ Yes [5]github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Premium Plan: All Plus plan features included. First 150,000 minutes monthly at no charge. Enterprise features: data isolation, encryption key management, mutual authentication. HIPAA readiness support. Requires direct sales contact for provisioning.”

• Real-time streaming
• Speaker diarization

Supported actions

transcribe_batch, transcribe_streaming, transcribe_websocket, transcribe_async_http, speaker_diarization, word_timestamps, interim_results, keyword_spotting, word_confidence_scores, smart_formatting, profanity_filtering, custom_language_model, custom_acoustic_model, language_identification, speech_activity_detection, transcript_enrichment, speech_begin_event_detection [6]cloud.ibm.com/docs/speech-to-text“IBM provides the Watson speech-to-text service over several different channels, such as REST, HTTP with webhook callbacks, and WebSockets.”cloud.ibm.com/docs/speech-to-text“Keyword spotting identifies spoken phrases from the audio that match specified keyword strings. Word timestamps reports confidence levels for each word. Profanity filter censors profanity from US English transcriptions.”

Regions

us-south (Dallas), us-east (Washington DC), eu-de (Frankfurt), eu-gb (London), au-syd (Sydney), jp-tok (Tokyo), kr-seo (Seoul) [7]cloud.ibm.com/apidocs/speech-to-text“IBM Watson Speech to Text is available in the following regions: Dallas (us-south), Washington DC (us-east), Frankfurt (eu-de), Sydney (au-syd), Tokyo (jp-tok), London (eu-gb), Seoul (kr-seo).”

Languages

English (US), English (UK), English (Australian), English (Indian), French (France), French (Canadian), German, Spanish (Castilian), Spanish (Argentinian), Spanish (Chilean), Spanish (Colombian), Spanish (Mexican), Spanish (Peruvian), Brazilian Portuguese, Japanese, Italian, Dutch, Swedish, Arabic [8]cloud.ibm.com/docs/speech-to-text“The service supports speech recognition for numerous languages including English (US, Australian, Indian, UK dialects), Japanese, French (France, Canadian), German, Spanish (Castilian, Argentinian, Chilean, Colombian, Mexican, Peruvian), Brazilian Portuguese, Dutch, Italian, Swedish, Arabic.”github.com/ibm-cloud-docs/speech-to-text/blob/master/release-notes.md“Large speech model for Italian, it-IT is now generally available (GA) as of May 2026, supporting both 8kHz and 16kHz audio.”

Input types

audio/wav, audio/mp3, audio/mpeg, audio/flac, audio/ogg, audio/ogg;codecs=opus, audio/ogg;codecs=vorbis, audio/webm, audio/webm;codecs=opus, audio/webm;codecs=vorbis, audio/l16, audio/alaw, audio/mulaw, audio/basic, audio/g729, WebSocket streaming, HTTP REST (batch), Asynchronous HTTP with callback URL [9]github.com/ibm-cloud-docs/speech-to-text/blob/master/audio-formats.md“The IBM Watson Speech to Text service supports these audio input formats: audio/wav, audio/mp3, audio/mpeg, audio/flac, audio/ogg (Opus and Vorbis codecs), audio/webm (Opus and Vorbis codecs), audio/l16, audio/alaw, audio/mulaw, audio/basic, audio/g729.”

Output types

JSON transcript, word timestamps, word confidence scores, speaker labels (diarization), keyword spotting results, interim results, WebVTT captions (via IBM Video Streaming integration) [10]cloud.ibm.com/docs/speech-to-text“IBM Watson Speech to Text returns JSON response content. The service reports word timestamps, word confidence scores, speaker labels (diarization), and keyword spotting results.”

Webhooks

✓ Yes [11]cloud.ibm.com/docs/speech-to-text“The service registers a callback URL for use with subsequent asynchronous recognition requests. The service attempts to register or allowlist the callback URL if it is not already registered by sending a GET request to the callback URL.”

Sandbox / test mode

✗ No [12]cloud.ibm.com/docs/speech-to-text“The Lite plan is free and provides 500 minutes of speech recognition per month at no cost.”

SDK languages

Python, Node.js, Java, Swift, Go [13]cloud.ibm.com/apidocs/speech-to-text“IBM Watson Speech to Text provides client libraries for Java, Node.js, Python, Ruby, Go, and .NET Standard.”watson-developer-cloud.github.io/swift-sdk/services/SpeechToTextV1/index.html“SpeechToTextV1 Reference — Watson Developer Cloud Swift SDK”

MCP server

✗ No [14]github.com/IBM/ibm-watsonxdata-mcp-server“IBM has an MCP server for watsonx.data but no official MCP server for Watson Speech to Text was found in IBM's official repositories or documentation.”

SOC 2

SOC 2 Type II [15]ibm.com/products/cloud/compliance/soc-2“IBM Cloud is SOC 2 compliant because it has implemented and maintained robust controls that meet SOC 2 requirements, and it undergoes regular, independent audits. Services issue SOC 2 Type 2 reports at least once each year.”ibm.com/new/announcements/ibm-public-cloud-soc-framework“IBM Public Cloud Services Added to SOC 1 Type 2, SOC 2 Type 2, and SOC 3 Reports”

HIPAA

✓ Yes [16]github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Premium Plan: HIPAA readiness support. Enterprise features: data isolation, encryption key management, mutual authentication.”cloud.ibm.com/docs/speech-to-text“IBM is committed to providing clients and partners with innovative data privacy, security and governance solutions to assist them on their journey to GDPR compliance. IBM clients who are subject to HIPAA and who wish to use IBM Cloud products for HIPAA regulated data must enter into a Business Associate Agreement (BAA) with IBM.”

GDPR

✓ Yes [17]cloud.ibm.com/docs/speech-to-text“IBM is committed to providing clients and partners with innovative data privacy, security and governance solutions to assist them on their journey to GDPR compliance.”

ISO 27001

✓ Yes [18]ibm.com/support/pages/ibm-iso-27001-certifications-cloud“IBM has obtained certificates to the ISO 27001 standard by country or business unit. IBM ISO 27001 certificates are published and generally available.”ibm.com/products/cloud/compliance/iso-27001“What is ISO/IEC 27001? | IBM”

PCI DSS

– Unknown [19]ibm.com/products/cloud/compliance/pci“IBM Cloud PCI DSS compliance”

Published SLA

✓ Yes [20]cloud.ibm.com/docs/overview“IBM provides a 99.9% uptime availability SLA for Watson Services in Premium or Dedicated deployment models configured for high availability if the services are provisioned across multiple environments in geographically separated data-centers within one IBM-specified Region.”

Rate limits

Lite plan: 500 minutes/month. Plus plan: maximum 100 concurrent transcription requests. Premium plan: unlimited concurrent transcription requests. No explicit per-request rate limit documented publicly beyond concurrency caps. [21]github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Maximum of 100 concurrent transcription requests [Plus plan]. Premium plan includes unlimited concurrent transcriptions.”cloud.ibm.com/docs/speech-to-text“Plus version includes unlimited minutes per month and 100 concurrent transcriptions, and the Premium plan includes unlimited minutes per month and unlimited concurrent transcriptions.”

Known restrictions

Lite plan services deleted after 30 days of inactivity, Lite plan has no access to customization (custom language/acoustic models), Standard plan no longer available for new purchases, Smart formatting limited to US English and Spanish, Profanity filter available for US English only, Speaker diarization language support varies by model generation, Audio billed by the minute including silence, Custom model training requires a paid plan (Plus or Premium), Premium plan requires direct IBM sales contact for provisioning [22]cloud.ibm.com/docs/speech-to-text“Smart formatting to control how the engine transcribes numbers and dates for U.S. English and Spanish. Profanity filter censors profanity from US English transcriptions by default.”github.com/ibm-cloud-docs/speech-to-text/blob/master/faq-pricing.md“Lite Plan: No customization access. Services deleted after 30 days of inactivity. Billing: Monthly aggregation rounded to nearest minute; all audio (including silence) counts toward usage totals.”

• Docs
• API reference

Docs rendering: static

API style

rest

Base URL

https://api.{location}.speech-to-text.watson.cloud.ibm.com/instances/{instance_id}

Version

v1

Versioning

url

Stability

ga

Auth methods

api_key, oauth2

Idempotency keys

✗ No

Error format

vendor-specific

Webhook signing

hmac_sha1

SDKs

• Python ibm-watson · repo
• Node.js ibm-watson · repo
• Java com.ibm.watson:ibm-watson · repo
• Swift IBMWatsonSpeechToTextV1 · repo
• Go github.com/watson-developer-cloud/go-sdk/v2 · repo

• Auth docs
• Quickstart
• Webhook events
• Deprecation policy

Launched

2015-01-01

GA

2024-08-23

Notable customers

Citibank, Bradesco, Humana

• ElevenLabs Scribe (Speech to Text)

  "Scribe v2 is the most accurate Speech to Text model" offering "real-time Speech to Text in under 150 ms" across "90+ languages."

  Hybrid · free tier · public pricing · self-serve

• Azure AI Speech to Text

  "Azure Speech in Foundry Tools provides speech to text, text to speech, and other capabilities through a Microsoft Foundry resource. You can transcribe speech to text with high accuracy, produce natural-sounding text-to-speech voices, translate spoken audio, and conduct live AI voice conversations."

  Usage · free tier · public pricing · self-serve

• Amazon Transcribe

  "Amazon Transcribe is an automatic speech recognition service that uses machine learning models to convert audio to text. You can use Amazon Transcribe as a standalone transcription service or to add speech-to-text capabilities to any application."

  Usage · free tier · public pricing · self-serve

• Google Cloud Speech-to-Text

  "Accurate voice typing and transcription powered by Gemini."

  Usage · free tier · public pricing · self-serve

• AssemblyAI

  "Voice AI infrastructure for developers building products that transcribe, understand, and act on speech."

  Usage · public pricing · self-serve

• Speechmatics

  "Low-latency speech-to-text for multilingual, multi-speaker conversations."

  Usage · free tier · public pricing · self-serve

IBM watsonx Speech to Text alternatives · IBM watsonx Speech to Text vs ElevenLabs Scribe (Speech to Text) · All Speech-to-Text & Transcription APIs APIs

Each field above carries a numbered source - hover for a preview, click to jump here.

1. ↑Description: cloud.ibm.com · ibm.com
2. ↑Pricing model: github.com · cloud.ibm.com
3. ↑Free tier: github.com · cloud.ibm.com
4. ↑Self-serve signup: cloud.ibm.com
5. ↑Enterprise plan: github.com
6. ↑Supported actions: cloud.ibm.com · cloud.ibm.com
7. ↑Regions: cloud.ibm.com
8. ↑Languages: cloud.ibm.com · github.com
9. ↑Input types: github.com
10. ↑Output types: cloud.ibm.com
11. ↑Webhooks: cloud.ibm.com
12. ↑Sandbox: cloud.ibm.com
13. ↑SDK languages: cloud.ibm.com · watson-developer-cloud.github.io
14. ↑MCP server: github.com
15. ↑SOC 2: ibm.com · ibm.com
16. ↑HIPAA: github.com · cloud.ibm.com
17. ↑GDPR: cloud.ibm.com
18. ↑ISO 27001: ibm.com · ibm.com
19. ↑PCI DSS: ibm.com
20. ↑Published SLA: cloud.ibm.com
21. ↑Rate limits: github.com · cloud.ibm.com
22. ↑Known restrictions: cloud.ibm.com · github.com

Every field change, who made it, and when - from our audited data pipeline and editors.

1. 2026-06-21 Capabilities: {} → {"real_time_streaming":true,"speaker_diarization":true}
2. 2026-06-21 Summary Md: (none) → IBM watsonx Speech to Text is a REST API for fast, accurate transcription suppo…
3. 2026-06-21 Score Setup Speed: (none) → 85
4. 2026-06-21 Score Pricing Transparency: (none) → 100
5. 2026-06-21 Score Docs Quality: (none) → 35
6. 2026-06-21 Score Procurement Friction: (none) → 100
7. 2026-06-21 Score Trust Readiness: (none) → 90
8. 2026-06-21 Best For: (none) → Prototypes and side projects - free to start, no sales call, Regulated or enter…
9. 2026-06-21 Scoring Methodology: (none) → Scores are computed deterministically from this profile's published, sourced fi…
10. 2026-06-21 Score Agent Friendliness: (none) → 30
11. 2026-06-21 Llms Txt Present: (none) → No
12. 2026-06-21 Rendering: (none) → static
13. 2026-06-21 Has Structured Data: (none) → Yes
14. 2026-06-21 API Reference URL: (none) → https://cloud.ibm.com/apidocs/speech-to-text
15. 2026-06-21 Docs URL: (none) → https://developer.ibm.com/
16. 2026-06-21 Robots Allows Agents: (none) → Yes
17. 2026-06-21 Pricing Model: set to usage_based
18. 2026-06-21 Has Published Pricing: set to Yes
19. 2026-06-21 Free Tier Available: set to Yes
20. 2026-06-21 Free Tier Details: set to Lite plan: 500 minutes per month at no cost (recurring monthly allowance). No c…
21. 2026-06-21 Self Serve Signup: set to Yes
22. 2026-06-21 Requires Sales Call: set to No
23. 2026-06-21 Enterprise Plan Available: set to Yes
24. 2026-06-21 SOC 2: set to type_2
25. 2026-06-21 HIPAA: set to Yes
26. 2026-06-21 GDPR: set to Yes
27. 2026-06-21 ISO 27001: set to Yes
28. 2026-06-21 SLA Published: set to Yes
29. 2026-06-21 SLA URL: set to https://cloud.ibm.com/docs/overview?topic=overview-slas
30. 2026-06-21 Data Retention Policy URL: set to https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-information-secu…
31. 2026-06-21 Documented Rate Limits: set to Lite plan: 500 minutes/month. Plus plan: maximum 100 concurrent transcription r…
32. 2026-06-21 Known Restrictions: set to Lite plan services deleted after 30 days of inactivity, Lite plan has no access…
33. 2026-06-21 Auth Methods: set to api_key, oauth2
34. 2026-06-21 Auth Docs URL: set to https://cloud.ibm.com/docs/watson?topic=watson-iam
35. 2026-06-21 API Style: set to rest
36. 2026-06-21 Base URL: set to https://api.{location}.speech-to-text.watson.cloud.ibm.com/instances/{instance_…
37. 2026-06-21 API Version: set to v1
38. 2026-06-21 Versioning Scheme: set to url
39. 2026-06-21 Stability: set to ga
40. 2026-06-21 Slug: set to ibm-watson-speech-to-text
41. 2026-06-21 Quickstart URL: set to https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-gettingStarted
42. 2026-06-21 Idempotency Supported: set to No
43. 2026-06-21 Error Format: set to vendor-specific
44. 2026-06-21 Webhook Signing: set to hmac_sha1
45. 2026-06-21 Webhook Events URL: set to https://cloud.ibm.com/docs/speech-to-text?topic=speech-to-text-async
46. 2026-06-21 Requires Verification: set to No
47. 2026-06-21 Starting Price Usd: set to 0.02
48. 2026-06-21 Price Basis: set to minute
49. 2026-06-21 Free Tier Limit: set to 500 minutes/month
50. 2026-06-21 Launched At: set to 2015-01-01

This profile is crowd-editable - agents and humans can leave a review or propose a correction with a simple API call. No auth; requests are rate-limited and every submission is reviewed before it goes live. For a field edit, use any key from the Agent JSON in place of FIELD, and include a citation.

curl -X POST https://apio.sh/api/feedback/ibm-watson-speech-to-text \
  -H 'Content-Type: application/json' \
  -d '{"kind":"review","rating":5,"body":"Your experience with this API…"}'

curl -X POST https://apio.sh/api/suggest/ibm-watson-speech-to-text/FIELD \
  -H 'Content-Type: application/json' \
  -d '{"value":"corrected value","citations":[{"url":"https://source.example/page","excerpt":"supporting quote"}],"note":"what changed and why"}'

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