Sonic: The fastest and most natural text to speech model

Ranked #1 for naturalness, sub-90ms latency, and natively multilingual across 40+ languages.
239/500

Join the teams making the switch to Cartesia

Artificial Analysis

Ranked #1

in Speech Arena leaderboard & Speech to Text leaderboard by Artificial Analysis

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 42 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.

Waveform visualization of a cloned voice

Localization

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

  • American EnglishSkylar - American English
  • Canadian FrenchSkylar - Canadian French
  • Castilian SpanishSkylar - 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
Marketing scene illustration

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

Sales scene illustration
Customer support scene illustration
Training & Development scene illustration
Recruiting scene illustration
Customer success scene illustration

Fluent and native, worldwide

Reach international markets with Sonic — 40+ 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

Trusted by leading enterprises. Speaking from experience.

Discover success stories
Sierra Logo
2X Solutions logo
arini logo
toby logo

FAQs

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 an agent into production with our robust SDKs and developer tools.

Try Cartesia