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Purchase credits and pay for what you consume across all models and products. Manage your credits in Portal Billing. Inworld offers four APIs: TTS, STT, Router (LLM), and Realtime API (Speech to Speech). You only pay for the underlying model usage each API consumes, with no markup on any product.

Plans

On-demand

For developers and scaling startups
ProductPrice
TTS-1.5 Mini$5/1M chars. (0.5¢/min)
TTS-1.5 Max$10/1M chars. (1¢/min)
RouterUnderlying LLM usage (rates below)
Realtime APIUnderlying TTS, STT, and LLM usage
  • #1 ranked TTS globally
  • Intelligent model routing
  • Semantic speech recognition
  • Realtime speech-to-speech
  • Instant voice cloning
  • 220+ LLM models
  • API access
  • 100 RPS TTS rate limit
  • GDPR & SOC 2 Type II
  • Support bot & community support
Get started for free

Enterprise

For large-scale deployments
ProductPrice
TTS-1.5 MiniVolume-based discounts
TTS-1.5 MaxVolume-based discounts
RouterVolume-based discounts
Realtime APIVolume-based discounts
  • All On-demand features
  • Professional voice cloning
  • Custom rate limits
  • On-prem deployment options
  • HIPAA & BAA
  • DPA & SLA
  • Zero data retention mode
  • EU and India data residency
  • Dedicated account manager & Slack channel
  • Invoicing options
Contact sales

Credit balance

Your credit balance is displayed at the top of the Billing page. Credits are consumed by API and Playground usage across all products (TTS, LLM, STT).
  • Add credits — Click Add credits to purchase more. The minimum purchase is $10. You will be redirected to a secure checkout page, and credits are applied immediately upon payment.
  • Auto-reload — Enable auto-reload to automatically purchase credits when your balance falls below a threshold you set. Configure the reload amount and threshold from the Billing page.
  • Negative balance — You may temporarily exceed your credit balance due to billing delays. Any overage is subtracted from your next credit purchase.
Enterprise accounts are billed per their agreement. The credit purchase UI is not available for enterprise plans.

TTS rates

Text-to-Speech usage is billed based on characters synthesized across both the TTS Playground and the API.
ModelPriceApproximate cost per minute
Inworld TTS-1.5-Max$10/1M characters~$0.01/min
Inworld TTS-1.5-Mini$5/1M characters~$0.005/min
Inworld TTS is also available for on-prem deployment for both TTS-1.5-Mini and TTS-1.5-Max. Contact sales for on-prem pricing.

STT rates

Speech-to-Text is available via both the standalone STT API and the Realtime API. Usage is billed based on audio duration.
ModelProviderPrice
Universal-Streaming MultilingualAssemblyAI$0.15/hour
If you need a model that is not listed, contact sales.

LLM rates

When you route LLM requests through Inworld, you pay the provider’s listed cost with no markup. Using Inworld’s Agent Runtime SDK is free — you only pay for model consumption. See the Pricing page for a full breakdown of LLM model rates across all supported providers.