Cartesia Sonic vs VoiceKeep
Cartesia Sonic
cartesia.ai
VoiceKeep
voicekeep.ioSide by side
| Figure | Cartesia Sonic | VoiceKeep |
|---|---|---|
| Price from | $5/mo | $5/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| API | Yes | Yes |
| Plans published | 6 | 5 |
| Spec score · Game Voice Generators | 8.6 (#12) | 7.6 (#32) |
| API access | Yes | The REST API supports voice management, text-to-speech, conversations, and audiobook creation; API keys are available on Pro and Studio. |
| Integrations | Managed Agents can use Cartesia-provisioned numbers, import Twilio numbers, or connect a carrier over SIP. | The maker describes M4B exports as compatible with Apple Books, Audible, and other audiobook players, and offers API integration for apps. |
| Product | Sonic is a text-to-speech model for real-time voice applications. | VoiceKeep is a browser-based AI voice platform for voice cloning, text-to-speech, conversations, audiobook production, and production-ready audio. |
| Security | Cartesia lists HIPAA compliance, SOC 2 Type 2, GDPR, and PCI on the Sonic page. | The privacy policy says VoiceKeep uses TLS encryption in transit and access controls, and processes voice data on its own GPU infrastructure rather than sending it to third-party AI providers. |
| Support | Cartesia's documentation directs users to Discord to chat with the Cartesia team and community for help. | The Studio plan includes priority human support, and pricing directs larger organizations seeking custom limits, SSO, or dedicated infrastructure to contact VoiceKeep for a quote. |
| Voice cloning | Instant voice cloning can use 10 seconds of audio, while Pro Voice Clone training uses 30 minutes or more from one speaker. | Users can create a custom voice clone by uploading a short voice sample; the FAQ specifies a 5–25 second clip with a matching transcript. |
Plans
Cartesia Sonic
- FreeFree
- Pro$5 a month
- Startup$49 a month
- Scale$299 a month
- FreeFree
- EnterprisePriced on request
VoiceKeep
- FreeFree
- Starter$5 a month
- Creator$19 a month
- Pro$49 a month
- Studio$149 a month
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.