Artificial AnalysisRanked #1 in Speech Arena

Sonic: the fastest, most realistic text to speech model

Expressive voices that laugh on cue and read order numbers exactly, with first audio in under 90ms, in 44 languages from one model.
242/500

Built for Voice Agents

Seven capabilities that make Sonic the voice layer production agents rely on.

A voice that reads the room.

In practice

The best voice interactions feel effortless — tone adjusts to context, pacing stays consistent, and the speech moves with the natural rhythm of how people actually talk.


Sonic's approach

By default, Sonic interprets the emotional subtext in the transcript and calibrates delivery automatically. Non-verbal expressions like laughter can be inserted directly into the transcript.

I can't believe we actually made it. [laughter] Finally!

Sonic features built for your voice

Clone your voice, localize it into 44 languages, and fine-tune every word.

Voice cloning

Clone any voice instantly with 10 seconds of audio. High speaker similarity means the brand voice you love stays true, even at scale.

Localization

Localize any audio clip with native-speaker quality. Emotion, tone, and speaker identity carry through — nothing gets lost in translation.

  • American EnglishEmma - American English
  • Canadian FrenchEmma - Canadian French
  • Castilian SpanishEmma - Castilian Spanish

Custom Pronunciation Dictionaries

Specify custom pronunciations for proper nouns, domain terms, and anything else that needs to sound exactly right.

  • WordPronunciation
  • charcuterieshar-koo-terie
  • subpoena<<s|ə|ˈ|p|i|n|ə>>
  • epinephrine<<ˌ|ɛ|p|ɪ|ˈ|n|ɛ|f|ɹ|ɪ|n>>

One voice model for your entire business.

See how enterprise teams use Sonic across every use case — and hear it for yourself.

Marketing

Calls warm leads the day a campaign fires, personalizes the opener, and books meetings in the CRM.

Fluent and native, worldwide

Reach international markets with Sonic — 44 languages and a wide range of accents, all with native-speaker quality voices.

Most popular locales

Enterprise-grade security.From Cloud to Local.

  • HIPAA compliant badge

    HIPAA compliant

  • SOC 2 Type 2 badge

    SOC 2 Type 2

  • GDPR badge

    GDPR

  • PCI badge

    PCI

FAQs

What makes Cartesia the best realtime TTS compared to other TTS models?

Cartesia is the only model where you don't have to pick between quality and speed. Our models are built on State Space Model (SSM) architecture — a fundamentally different approach to transformers, pioneered by our founding team at Stanford. For text-to-speech, this translates into three things that matter at production scale: lowest latency in the market (Sonic delivers sub-90ms model latency, with streaming support that lets playback begin before the full response is generated); lower cost and higher concurrency (SSMs are computationally more efficient than transformers on long sequences); and state-of-the-art naturalness (higher accuracy on alphanumerics and heteronyms, and #1 ranked on third-party blind benchmarks for naturalness). Teams typically choose Cartesia when they've hit the limits of other providers on latency, reliability-at-scale, or deployment flexibility.

Can Cartesia run on-prem or in my own cloud (VPC)?

Yes, and this is one of the main reasons enterprise and government buyers choose Cartesia. Sonic-3.6 can be deployed on-prem inside your data center (including air-gapped environments), in your own VPC on AWS/GCP/Azure, or via OEM licensing for embedding Sonic directly into your product. This makes Cartesia viable for government contracting, regulated industries (healthcare, financial services, insurance), and customers with data sovereignty or residency requirements. On-prem and OEM deployments are available under enterprise contracts.

How does Cartesia handle data privacy, compliance, and security?

Cartesia is built for enterprise and regulated industry deployments. Our compliance posture includes SOC 2 Type II, HIPAA-eligible (with BAAs available for healthcare customers), GDPR-compliant, zero data retention available for enterprise customers across eligible services, and on-prem/VPC deployment for customers with strict data residency, sovereignty, or air-gapped requirements. Our Data Protection Addendum can be found at https://www.cartesia.ai/legal/dpa.

Can I create voices with Cartesia?

You can clone voices you have the right to clone. Cartesia offers Instant Voice Cloning from a short reference sample (under a minute of clean audio), Professional Voice Cloning from longer reference audio (15–30 minutes) for the highest-fidelity clones in production, and custom voice development under enterprise contracts for customers building branded voices at scale. All voice clones require verified consent from the speaker. Cloning voices you don't have permission to use — including public figures, celebrities, or other people without their consent — is prohibited under Cartesia's Terms of Use. Cloned voices work across Sonic TTS, the API, and Managed Agents.

What do Cartesia's plans cost, and what's included?

Cartesia offers plans across three tiers. Free: for evaluation and personal use, includes 20K credits and access to Sonic, the API, voices, and Instant Voice Cloning. Paid self-serve plans: for teams shipping to production, includes commercial usage rights, higher credit allotments, higher concurrency, and faster generation; pricing is at https://www.cartesia.ai/pricing. Enterprise: for high-volume production, on-prem and VPC deployment, OEM licensing, custom voices, zero data retention, and higher SLAs, with custom pricing based on usage and deployment model. Cartesia also offers a startup grants program at https://www.cartesia.ai/startups with credits for qualifying early-stage companies.

When should I contact Sales?

Reach out to the Cartesia team if you're running high-volume production workloads (>50M credits); you need on-prem, VPC, or OEM deployment; you need a BAA, zero data retention, or other contractual compliance terms for healthcare, financial services, or regulated sectors; or you're in government, federal, or public sector procurement. For everything else — evaluation, prototyping, smaller production workloads — the self-serve plans on the pricing page will get you started.

Get started today

Talk to an expert.

Connect with a member of our team and learn how Cartesia can help you build world-class voice experiences.

Contact Sales

Start building.

Access our models via API and bring a voice agent into production in minutes.

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