Cartesia Sonic vs Inworld AI
Cartesia Sonic
cartesia.ai
Inworld AI
inworld.aiSide by side
| Figure | Cartesia Sonic | Inworld AI |
|---|---|---|
| Price from | $5/mo | $25/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 6 | 6 |
| Spec score · Game Voice Generators | 8.6 (#12) | 8.2 (#19) |
| Headquarters | San Francisco, California, United States | Mountain View, California, United States |
| Integrations | Managed Agents can use Cartesia-provisioned numbers, import Twilio numbers, or connect a carrier over SIP. | The documentation lists OpenAI compatibility and a Twilio telephony integration for Realtime TTS. |
| Product | Sonic is a text-to-speech model for real-time voice applications. | Inworld describes itself as a research lab and inference provider for realtime AI at consumer scale, with first-party TTS and STT models and customer-selected LLMs. |
| Security | Cartesia lists HIPAA compliance, SOC 2 Type 2, GDPR, and PCI on the Sonic page. | Inworld states it has SOC 2 Type II certification and HIPAA and GDPR compliance, and describes AES encryption for data at rest and in transit. |
| Support | Cartesia's documentation directs users to Discord to chat with the Cartesia team and community for help. | The pricing page lists community support on On-Demand through Builder, priority email support on Developer and Growth, and an account manager plus Slack channel for Enterprise. |
Plans
Cartesia Sonic
- FreeFree
- Pro$5 a month
- Startup$49 a month
- Scale$299 a month
- FreeFree
- EnterprisePriced on request
Inworld AI
- On-DemandFree
- Creator$25 a month
- Builder$100 a month
- Developer$300 a month
- Growth$1,500 a month
- EnterprisePriced on request
In their own words
Cartesia Sonic
Cartesia Sonic is a text-to-speech model for real-time voice applications, available through the web and an API. It has sub-90ms latency and supports 44 languages. Sonic can interpret emotional subtext and add non-verbal expressions such as laughter to transcripts. Its localization feature carries emotion, tone, and speaker identity into another language, while custom pronunciation dictionaries let users set how proper nouns and domain terms are spoken. For voice agents, Managed Agents combine Ink-2 speech-to-text, a selected LLM, and Sonic-3.6 text-to-speech, with turn-taking and interruption handling. Phone connectivity can use Cartesia-provisioned numbers, imported Twilio numbers, or a carrier over SIP. Cartesia lists HIPAA compliance, SOC 2 Type 2, GDPR, and PCI. It says Sonic can be deployed on-premise, in a customer VPC on AWS, GCP, or Azure, or through OEM licensing. A free plan includes 20K credits per month and two concurrent text-to-speech requests. Paid plans start at $5/mo; higher tiers raise credit allowances and list capabilities including organizations and priority support.