Audience
Developers, product teams, and enterprises seeking to build fast, natural, multilingual voice agents and text-to-speech experiences for customer-facing and business workflows
About Cartesia Sonic-3.6
Sonic is a real-time text-to-speech model built for voice agents, combining natural delivery, sub-90ms latency, and native support for more than 40 languages. It is designed to make voice interactions feel effortless, with tone that adjusts to context, consistent pacing, and speech that follows the natural rhythm of conversation. By default, Sonic interprets the emotional subtext of a transcript and calibrates delivery automatically, while non-verbal expressions such as laughter can be inserted directly into the text. The model follows transcripts faithfully, produces clean audio across languages and voices, and handles alphanumeric content such as order numbers, phone numbers, IDs, and email addresses naturally without preprocessing. Context-aware pronunciation helps heteronyms sound correct from surrounding words, while custom pronunciation dictionaries let teams define how proper nouns and domain-specific terms should be spoken.
Other Popular Alternatives & Related Software
Dessa
Dessa is Block's speech-to-speech artificial intelligence model for conversational voice research and applications. It takes audio input and produces audio output directly, without converting speech into text as an intermediate step. Trained from scratch on human conversation rather than text, the model supports full-duplex interaction, listening and speaking at the same time, and runs locally on a MacBook Pro with an M4 Max chip or better. It captures conversational cues such as emotion, sarcasm, laughter, pauses, and turn-taking that can be lost in text-based pipelines. Dessa is intended for AI safety researchers and developers studying voice-model behavior, privacy, and real-time interaction. It is a speech model for research and development, not a general-purpose business application or hosted voice-agent platform.
Learn more about Dessa
Grok Voice 3.0
Grok Voice 3.0 is a speech-to-speech model offered through the Grok Voice Agent API for developers building real-time voice applications. It accepts audio and text and returns spoken audio or text through a WebSocket session, supporting conversational turn-taking, interruptions, and function calling. Developers can connect the model to custom functions and server-side tools, including web search, X search, collections, and remote MCP servers. The API is intended for interactive voice agents such as customer-support and service-call experiences, and is also used for voice interactions in Tesla vehicles and Grok Bot. Billing is usage-based, with audio charged per minute and text input events billed separately. The API documentation includes setup instructions and examples for Python and JavaScript clients.
Learn more about Grok Voice 3.0
Gradium
Gradium is a voice AI platform for developers and organizations building speech-enabled applications and conversational agents. Its hosted APIs provide streaming text-to-speech, speech-to-text, speech translation, and speech-to-speech, with WebSocket and REST interfaces, real-time turn detection, pronunciation controls, and voice design or cloning features. A browser-based studio lets users try the models and manage voices, while documentation and SDK guides support application development. Use cases include voice agents, customer-service automation, live transcription, multilingual voice experiences, and spoken content generation. Gradium also publishes Phonon, an open-weight text-to-speech model designed for local, offline use in applications and on-device systems. Plans use credits for speech generation, transcription, and translation.
Learn more about Gradium
Eleven v4
Eleven v4 is a text-to-speech model from ElevenLabs for generating expressive spoken audio from written scripts. It supports multi-speaker dialogue, emotional direction and audio-event tags, voice cloning, and consistent speaker identity across generated scenes. Creators, publishers, and production teams can use it for narration, audiobooks, character dialogue, video and game voiceovers, and multilingual projects. Developers can generate speech through the ElevenLabs web application or API; the related Eleven v4 Turbo model is intended for real-time speech and voice-agent scenarios. Eleven v4 supports 90+ languages. A free plan includes monthly credits for personal use, while paid plans provide higher credit limits and additional features.
Learn more about Eleven v4
Pricing
Starting Price:
$5 per month
Free Version:
Free Version available.
Free Trial:
Free Trial available.
Integrations
API:
Yes, Cartesia Sonic-3.6 offers API access
No integrations listed.
Company Information
Cartesia
Founded: 2023
United States
www.cartesia.ai/sonic
Videos and Screen Captures
Other Useful Business Software
Save Up to 91% on Cloud Compute With Spot VMs
Run batch jobs at 60-91% off with Spot VMs. Long-running workloads get automatic discounts with sustained use.
Product Details
Platforms Supported
Cloud
Training
Documentation
Support
Online
Cartesia Sonic-3.6 Frequently Asked Questions
Q: What kinds of users and organization types does Cartesia Sonic-3.6 work with?
Cartesia Sonic-3.6 works with these users and organization types: Mid Size Business, Small Business, Enterprise, Freelance, Nonprofit, Government, and Startup.
Q: What languages does Cartesia Sonic-3.6 support in their product?
Cartesia Sonic-3.6 supports these languages: English.
Q: What kind of support options does Cartesia Sonic-3.6 offer?
Cartesia Sonic-3.6 offers support via online.
Q: Does Cartesia Sonic-3.6 have an API?
Yes, Cartesia Sonic-3.6 has an API.
Q: What type of training does Cartesia Sonic-3.6 provide?
Cartesia Sonic-3.6 provides training in the form of documentation.
Q: Does Cartesia Sonic-3.6 offer a free trial?
Yes, Cartesia Sonic-3.6 offers a free trial.
Q: How much does Cartesia Sonic-3.6 cost?
Pricing for Cartesia Sonic-3.6 starts at $5 per month.
