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Cartesia Sonic-3

Free · From $4/yr

Sonic-3 makes AI voices sound truly human, adding natural emotions, laughter, and real-time responses faster than a blink. It turns text into lifelike speech across 40+ languages and offers voice cloning, perfect for creating engaging AI agents in customer service or interactive games.

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OverviewFeaturesUse CasesFAQIntegrationsPricing

About Cartesia Sonic-3

Who It's For

This tool is for developers creating AI agents that need to speak naturally. It's perfect for customer service bots, game characters, or virtual assistants. Companies wanting their AI to speak multiple languages or have a unique, branded voice will find it very useful.

What You Get

You get incredibly natural AI voices with human emotions and even laughter. Speech is super fast, ensuring conversations flow smoothly without delays. It supports over 40 languages and lets you create custom brand voices instantly.

How It Works

Developers integrate Sonic-3 using simple code tools. They send text, optionally adding emotional tags. The system instantly converts this into spoken audio, streaming it back in real-time. This advanced AI ensures conversations feel natural and quick.

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Features & Capabilities

🗣️ Expressive Voice Generation

Emotional Speech

Generates voices that can laugh and express a range of emotions like excitement or sadness, enhancing naturalness.

Natural Conversational Tone

Produces speech that closely mimics human conversational patterns for more engaging interactions.

Acronym & Initialism Handling

Intelligently processes acronyms and initialisms, reading them correctly based on contextual conventions.

⚡ Performance & Scalability

Ultra-Low Latency

Delivers text-to-speech responses with sub-100ms latency, outperforming human conversational thresholds.

Real-Time Responses

Designed for instant interactions, ensuring conversations feel seamless and fluid without lag.

Scalable Global Performance

Maintains consistent, low-latency performance across various regions worldwide, proven at enterprise scale.

🌍 Global Language & Voice Capabilities

Extensive Multilingual Support

Supports over 40 languages, covering 95% of the world, with authentic native voices.

Diverse Voice Library

Offers a comprehensive collection of curated voices to create various personas and engaging agents.

Instant Voice Cloning

Allows for rapid creation of custom voice clones in seconds, including fine-tuned professional versions.

⚙️ Developer Tools & Enterprise Readiness

API & SDKs

Provides simple, well-documented APIs and pre-built SDKs for seamless integration into existing products.

Interactive Playground

Enables instant experimentation with voice interactions, script testing, and voice customization directly in the browser.

Enterprise-Grade Compliance

Ensures secure and compliant operations with certifications including SOC 2 Type II, HIPAA, and PCI Level 1.

Use Cases

Transforming Real-time Customer Support with Empathetic AI Voices

Businesses struggle with robotic and slow AI customer support that frustrates users. Sonic-3 leverages ultra-low latency and emotionally expressive voices to create seamless, natural conversations, significantly improving customer satisfaction and agent efficiency.

Customer ServiceFor: Customer Service Managers

Creating Engaging & Localized AI Characters for Gaming and Metaverse

Developers face challenges in making game characters and AI avatars sound natural and emotionally responsive, especially across diverse global audiences. Sonic-3's naturalness, emotional range, multi-language support, and voice cloning enable the creation of highly immersive and culturally relevant interactive experiences.

GamingFor: Game Developers

Scaling Global Outreach with Native and Empathetic AI Voices

Expanding into international markets for sales and recruiting requires automated communication that is both culturally fluent and builds rapport. Sonic-3 allows companies to deploy AI agents with native-sounding voices in 40+ languages and custom voice clones, ensuring authentic and effective engagement with a global audience at scale.

SalesFor: Sales Development Teams

Improving Patient Experience with Trustworthy AI Voice Assistance

Healthcare organizations need to provide clear, empathetic, and trustworthy information to patients through automated channels. Sonic-3 offers friendly, natural, and context-savvy voices that simplify appointment scheduling and clarify benefits, fostering patient confidence and improving the overall care experience.

HealthcareFor: Healthcare Administrators

Frequently asked questions

Cartesia Sonic 3 is a streaming text-to-speech (TTS) model that converts written text into ultra-realistic, expressive speech with exceptionally low latency, typically starting audio in about 90 milliseconds. It acts as the "vocal cords" for AI agents to enable fluid, natural voice conversations with human-like emotion, tone, and even laughter.

It uses advanced State Space Models (SSMs), an AI architecture that is much more efficient than traditional Transformer models. This efficiency results in near-zero latency voice generation, critical for seamless back-and-forth conversations.

Sonic 3 offers several features including low latency with approximately 90ms time to first audio for smooth real-time conversations, emotional expression through tags in input text supporting emotions such as excitement, sadness, and laughter, multi-language support for over 40 languages with highly natural, localized voices, voice cloning which can create custom voice clones from a few seconds of audio for brand consistency, and fine-grained control via API and SSML tags to manage volume, speed, emotion, and pronunciation.

No. Sonic 3 is focused solely on voice generation. It does not include knowledge retrieval, workflow automation, or analytics needed for fully featured AI customer support systems. Those components require integration with additional platforms and developer efforts.

Typical use cases for Sonic 3 include real-time voice AI agents for customer service, interactive game characters, AI avatars and narration with expressive speech, and global applications demanding native-sounding voices.

Developers access Sonic 3 via APIs or SDKs that allow text input with optional control parameters for emotion, speed, and volume. The system streams back audio in real-time suitable for conversational apps. Developers can integrate it into apps but must build complementary components like knowledge management themselves.

Cartesia offers a credit-based pricing system with tiered plans ranging from free personal use to enterprise plans for higher concurrency and support. Voice cloning services typically charge based on generated characters with no upfront cost for creating a clone.

You can adjust voice characteristics using SSML tags and API parameters to set volume, speech speed, emotional tone, and use laughter tags for natural effects. This customization lets applications adapt the voice to context, making conversations more empathetic or engaging.

Tags

automated customer supporttext-to-audiovirtual assistantvoice cloningconversational ai agent

Specifications

Deployment
API
Browser
Target Audience
Individual
Startup
Business
Enterprise
Complexity
Developer

Pricing

Free

Per monthly

Free
  • Get introduced to ultra-low latency voice AI through core models and your own voice agent
  • 20K credits for models
  • 1 prepaid for agents
  • Personal use
  • Discord support

Pro

Per annually

$4
  • Upgrade for instant voice cloning and to try voice AI in production for commercial use
  • 100K credits for models
  • 5 prepaid for agents
  • Instant voice cloning
  • Commercial Use

Startup

Per annually

$39
  • For teams starting to use voice AI in production and need shared API keys, pro voice cloning, and multiple agents
  • 1.25M credits for models
  • 49 prepaid for agents
  • Pro voice cloning
  • Organizations

Scale

Per annually

$239
  • For businesses with large-scale use cases requiring high concurrencies and multiple agents
  • 8M credits for models
  • 299 prepaid for agents
  • Priority support
  • High concurrency limits

Enterprise

Per annually

Contact sales
  • Custom supported models and agents with mission-critical guarantees for uptime, security, and compliance
  • Custom usage pricing
  • Custom concurrency
  • Priority and Enterprise support via Slack
  • Enterprise-grade security & compliance
  • Single Sign-On (SSO)
  • PCI compliance
  • Custom SLAs
  • Custom Security Review
  • HIPAA compliance

✓ Free plan • ✓ Plans from $4 / annually • ✓ Enterprise options

Integrations

ServiceNow
GitHub

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Links

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