apio

Hume AI Octave TTS

"Text-to-speech with emotional intelligence. Generate expressive, natural-sounding speech that conveys the full range of human emotion." [1]

www.hume.ai/octave · By Hume AI · Agent JSON · Suggest an edit · Last verified 2026-06-21 · Source confidence: high

Hume AI Octave is a text-to-speech API focused on emotionally expressive, natural-sounding voice synthesis, targeting voice agents, audiobooks, podcasts, and conversational applications. Pricing starts at $50 per million characters with a free tier of 10,000 characters per month, self-serve signup, and an enterprise plan for higher volume. SDKs are available for Python, TypeScript, C#/.NET, and Swift, and the API supports WebSocket streaming with first-audio latency as low as 100ms on Octave 2. The service holds SOC 2 Type 2, HIPAA, and GDPR certifications.

Best for / Avoid if

Best for: Prototypes and side projects - free to start, no sales call; Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt)

Pricing & procurement

Pricing model
Hybrid (base + usage) [2]
Published pricing
Yes
Free tier
Yes [3]
Free tier details
Free plan at $0/month includes 10,000 characters (~10 minutes) per month; non-commercial use only; rate limited to 15 RPM. [4]
Self-serve signup
Yes [5]
Requires sales call
No
Enterprise plan
Yes [6]
Published prices
PlanItemPerAmountSource
FreeSpeech synthesis monthly planmonth$0source
FreeSpeech synthesis included characters10,000 characters/month$0source
FreeSpeech synthesis overage1,000 characters$0.15source
StarterSpeech synthesis monthly planmonth$3source
StarterSpeech synthesis included characters30,000 characters/month$0source
StarterSpeech synthesis overage1,000 characters$0.15source
CreatorSpeech synthesis monthly planmonth$7source
CreatorSpeech synthesis included characters140,000 characters/month$0source
CreatorSpeech synthesis overage1,000 characters$0.15source
ProSpeech synthesis monthly planmonth$70source
ProSpeech synthesis included characters1,000,000 characters/month$0source
ProSpeech synthesis overage1,000 characters$0.12source
ScaleSpeech synthesis monthly planmonth$200source
ScaleSpeech synthesis included characters3,300,000 characters/month$0source
ScaleSpeech synthesis overage1,000 characters$0.1source
BusinessSpeech synthesis monthly planmonth$500source
BusinessSpeech synthesis included characters10,000,000 characters/month$0source
BusinessSpeech synthesis overage1,000 characters$0.05source

Capabilities

  • Real-time streaming
  • Voice cloning
  • Voice design
  • Multilingual voices
  • Word timestamps
Supported actions
synthesize_speech, streaming_tts, websocket_streaming, instant_voice_cloning, voice_design, word_timestamps, phoneme_timestamps, acting_instructions, multilingual_synthesis, continuation_context, audio_normalization, speed_control, multi_generation_per_request [7]
Regions
US
Languages
English, Spanish, Japanese, Korean, French, Portuguese, Italian, German, Russian, Hindi, Arabic [8]
Input types
plain text, utterance objects with acting instructions/description [9]
Output types
mp3, wav, pcm [10]
Webhooks
No
Sandbox / test mode
No
SDK languages
Python, TypeScript/Node.js, C#/.NET, Swift, Node.js CLI [11]
MCP server
Yes [12]

Trust & compliance

SOC 2
SOC 2 Type II [13]
HIPAA
Yes [14]
GDPR
Yes [15]
ISO 27001
Unknown
PCI DSS
Unknown
Published SLA
No [16]
Rate limits
Rate limits are per subscription tier (RPM): Free/Starter: 15 RPM; Creator: 75 RPM; Pro: 75 RPM; Scale: 150 RPM; Business: 225 RPM; Enterprise: custom. First audio latency (TTFB): Octave 1 ~200ms; Octave 2 ~100ms; instant mode typically ~200ms. [17]
Known restrictions
Maximum 5,000 characters per Utterance, Maximum 1,000 characters per description per Utterance, Maximum 5 generations per request, Speed control range: 0.75x–1.5x multiplier, Free and Starter plans: non-commercial use only, Voice design (custom voice from description) is English only in Octave 2 (multilingual coming soon), Voice cloning requires Octave 2, Instant mode unavailable for non-streaming endpoints, Requests using Octave 2 without a voice will be rejected, Users grant Hume a perpetual license to use voice recordings and voice models for service provision and product development, HIPAA-covered entities require an executed Business Associate Agreement (BAA) [18]

Developer surface

Docs rendering: static

Integration

API style
rest
Base URL
https://api.hume.ai
Version
v0
Versioning
url
Stability
ga
Auth methods
api_key, oauth2
Error format
vendor-specific (application/json with HTTPValidationError schema; detail array for 422)
Rate limit
15 / minute

SDKs

  • Python hume · repo
  • TypeScript/Node.js hume · repo
  • C#/.NET Hume · repo
  • Swift · repo
  • Node.js CLI @humeai/cli · repo

Adoption & maturity

Launched
2025-02-26
GA
2025-02-26
Notable customers
Niantic Spatial, GAF, Coconote

Other Text-to-Speech APIs

  • ElevenLabs Text to Speech

    "Text to Speech with high quality, human-like AI voices"

    Hybrid · free tier · public pricing · self-serve

  • Azure AI Text to Speech

    "Text to speech enables your applications, tools, or devices to convert text into human like synthesized speech. The text to speech capability is also known as speech synthesis. Use human like standard voices out of the box, or create a custom voice that's unique to your product or brand."

    Usage · free tier · public pricing · self-serve

  • Amazon Polly

    "Amazon Polly is a cloud service that converts text into lifelike speech. You can use Amazon Polly to develop applications that increase engagement and accessibility."

    Usage · free tier · public pricing · self-serve

  • Google Cloud Text-to-Speech

    "Cloud Text-to-Speech converts text or Speech Synthesis Markup Language (SSML) input into audio data of natural human speech."

    Usage · free tier · public pricing · self-serve

  • Cartesia (Sonic)

    "The fastest and most natural text to speech model"

    Hybrid · free tier · public pricing · self-serve

  • Murf AI

    "Enterprise-grade AI voice generation with 150+ natural-sounding voices across 35 languages and 20+ speaking styles."

    Usage · public pricing · self-serve

Hume AI Octave TTS alternatives · Hume AI Octave TTS vs ElevenLabs Text to Speech · All Text-to-Speech APIs APIs

References

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

  1. ↑Description: hume.ai
  2. ↑Pricing model: hume.ai
  3. ↑Free tier: hume.ai
  4. ↑Free tier details: hume.ai · dev.hume.ai
  5. ↑Self-serve signup: app.hume.ai
  6. ↑Enterprise plan: hume.ai
  7. ↑Supported actions: dev.hume.ai · dev.hume.ai
  8. ↑Languages: dev.hume.ai · dev.hume.ai
  9. ↑Input types: dev.hume.ai
  10. ↑Output types: dev.hume.ai · dev.hume.ai
  11. ↑SDK languages: dev.hume.ai · dev.hume.ai
  12. ↑MCP server: dev.hume.ai
  13. ↑SOC 2: hume.ai · hume.ai
  14. ↑HIPAA: dev.hume.ai · hume.ai
  15. ↑GDPR: dev.hume.ai · hume.ai
  16. ↑Published SLA: hume.ai
  17. ↑Rate limits: hume.ai · dev.hume.ai
  18. ↑Known restrictions: dev.hume.ai · dev.hume.ai · dev.hume.ai

Change history

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

  1. 2026-06-21 Capabilities: {} → {"streaming":true,"multilingual":true,"voice_design":true,"voice_cloning":true,…
  2. 2026-06-21 Summary Md: (none) → Hume AI Octave is a text-to-speech API focused on emotionally expressive, natur…
  3. 2026-06-21 Score Pricing Transparency: (none) → 100
  4. 2026-06-21 Score Agent Friendliness: (none) → 40
  5. 2026-06-21 Score Setup Speed: (none) → 85
  6. 2026-06-21 Score Docs Quality: (none) → 35
  7. 2026-06-21 Score Procurement Friction: (none) → 100
  8. 2026-06-21 Score Trust Readiness: (none) → 55
  9. 2026-06-21 Best For: (none) → Prototypes and side projects - free to start, no sales call, Regulated or enter…
  10. 2026-06-21 Scoring Methodology: (none) → Scores are computed deterministically from this profile's published, sourced fi…
  11. 2026-06-21 Robots Allows Agents: (none) → Yes
  12. 2026-06-21 API Reference URL: (none) → https://dev.hume.ai/reference
  13. 2026-06-21 Status Page URL: (none) → https://status.hume.ai
  14. 2026-06-21 Docs URL: (none) → https://dev.hume.ai/intro
  15. 2026-06-21 Rendering: (none) → static
  16. 2026-06-21 Llms Txt Present: (none) → No
  17. 2026-06-21 Has Structured Data: (none) → No
  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 Free plan at $0/month includes 10,000 characters (~10 minutes) per month; non-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 SLA Published: set to No
  28. 2026-06-21 Data Retention Policy URL: set to https://www.hume.ai/api-data-usage-policy
  29. 2026-06-21 Documented Rate Limits: set to Rate limits are per subscription tier (RPM): Free/Starter: 15 RPM; Creator: 75 …
  30. 2026-06-21 Rate Limit Requests: set to 15
  31. 2026-06-21 Rate Limit Window: set to minute
  32. 2026-06-21 Known Restrictions: set to Maximum 5,000 characters per Utterance, Maximum 1,000 characters per descriptio…
  33. 2026-06-21 Auth Methods: set to api_key, oauth2
  34. 2026-06-21 Auth Docs URL: set to https://dev.hume.ai/docs/introduction/api-key
  35. 2026-06-21 API Style: set to rest
  36. 2026-06-21 Base URL: set to https://api.hume.ai
  37. 2026-06-21 API Version: set to v0
  38. 2026-06-21 Versioning Scheme: set to url
  39. 2026-06-21 Stability: set to ga
  40. 2026-06-21 MCP URL: set to https://github.com/HumeAI/mcp-server-hume
  41. 2026-06-21 Quickstart URL: set to https://dev.hume.ai/docs/text-to-speech-tts/quickstart/python
  42. 2026-06-21 Error Format: set to vendor-specific (application/json with HTTPValidationError schema; detail array…
  43. 2026-06-21 Requires Verification: set to No
  44. 2026-06-21 Slug: set to hume-octave
  45. 2026-06-21 Price Basis: set to 1M characters
  46. 2026-06-21 Free Tier Limit: set to 10,000 characters/month
  47. 2026-06-21 Launched At: set to 2025-02-26
  48. 2026-06-21 GA Date: set to 2025-02-26
  49. 2026-06-21 Notable Customers: set to Niantic Spatial, GAF, Coconote
  50. 2026-06-21 Fields Not Found: set to iso_27001, pci_dss, sla_published, supported_regions_explicit, webhooks_support…

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