Updated February 24, 2025

Compare Cartesia and ElevenLabs Voice AI Models

Q: How does voice cloning work?

Voice cloning uses advanced AI algorithms to analyze and replicate a person's voice. By inputting a short audio sample, the system learns the unique characteristics of the voice, including tone, pitch, and accent. This allows for the generation of new speech that sounds like the original speaker. Cartesia's technology ensures high fidelity and accuracy, making the cloned voice indistinguishable from the original.

Q: What is the latency for voice generation?

Cartesia's voice generation technology boasts an impressive latency of just 40ms for time-to-first-audio. This means that users can expect near-instantaneous responses when generating speech. This low latency is crucial for applications requiring real-time interaction, such as customer support and gaming, where delays can disrupt the user experience.

Q: Can I customize the cloned voice?

Yes, Cartesia allows users to customize the cloned voice by adjusting parameters such as pitch, speed, and emotion. This flexibility enables users to create a voice that fits their specific needs, whether for storytelling, customer service, or other applications. The customization options enhance the overall user experience by making the generated speech more relatable and engaging.

Q: How many languages does Cartesia support?

Cartesia supports seamless speech in 15 languages, including English, Spanish, French, German, Japanese, and more. This multilingual capability allows users to reach a global audience, making it easier to create content that resonates with diverse populations. The platform continuously adds more languages, ensuring that users can communicate effectively across different regions.

Discover key differences between Cartesia and ElevenLabs voice AI models.

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Compare Cartesia and ElevenLabs Voice AI Models

Sonic outperforms ElevenLabs Flash V2 with better voice naturalism (61.4% preference in blind tests), faster performance (40ms vs 75ms model latency), and superior features including instant voice cloning (3s vs 30s audio required) and comprehensive voice delivery controls.

Latency

40ms for the Sonic Turbo model, 90ms for the Sonic 2.0 model

75 ms for the lower quality Flash Model, and 300ms+ for the full model

Voice Quality

Consistently rated as more natural, expressive, and realistic in blinded human evaluations

Less depth and reliability ratings in human evals

Character Limits

Infinite request length

Limited to 40k characters per request

Instant Cloning

Requires 3 seconds of audio

Requires 10 seconds of audio

Professional Voice Cloning

Requires 30 minutes of audio

Requires 60 minutes of audio

Pronunciation Accuracy

IPA support with strong contextual understanding

IPA support, isolated pronunciation

Voice Customizations

Fully customizable voice with speed and emotion controls + synthetic voice mixing and design

Stability, similarity, and style exaggeration controls

Telephony Optimization

8kHz audio, telephony optimized voices

Flexible deployments

Supports both on-prem and on-device deployments

No on-device or on-prem support

Languages Supported

15 languages with extensive dialect coverage

Concurrency

Up to 15 on highest self-serve tier (60 parallel conversations), custom for enterprise

Up to 15 on highest self serve tier, custom for enterprise

Latency

Cartesia 40ms for the Sonic Turbo model, 90ms for the Sonic 2.0 model

ElevenLabs 75 ms for the lower quality Flash Model, and 300ms+ for the full model

Voice Quality

Cartesia Consistently rated as more natural, expressive, and realistic in blinded human evaluations

ElevenLabs Less depth and reliability ratings in human evals

Character Limits

Cartesia Infinite request length

ElevenLabs Limited to 40k characters per request

Instant Cloning

Cartesia Requires 3 seconds of audio

ElevenLabs Requires 10 seconds of audio

Professional Voice Cloning

Cartesia Requires 30 minutes of audio

ElevenLabs Requires 60 minutes of audio

Pronunciation Accuracy

Cartesia IPA support with strong contextual understanding

ElevenLabs IPA support, isolated pronunciation

Voice Customizations

Cartesia Fully customizable voice with speed and emotion controls + synthetic voice mixing and design

ElevenLabs Stability, similarity, and style exaggeration controls

Telephony Optimization

Cartesia 8kHz audio, telephony optimized voices

ElevenLabs 8kHz audio, telephony optimized voices

Flexible deployments

Cartesia Supports both on-prem and on-device deployments

ElevenLabs No on-device or on-prem support

Languages Supported

Cartesia 15 languages with extensive dialect coverage

ElevenLabs 32

Concurrency

Cartesia Up to 15 on highest self-serve tier (60 parallel conversations), custom for enterprise

ElevenLabs Up to 15 on highest self serve tier, custom for enterprise

Cartesia - Faster and More Natural Voices

High-Quality Voice Cloning

Cartesia's voice cloning delivers lifelike, accurate voice replication with unmatched fidelity, only requires 3 seconds of audio.

Ultra-Realistic Voices

With a model latency of just 40ms, Sonic provides the fastest and most realistic voice generation available.

No Hallucinations

Cartesia's AI text to speech eliminates errors, accurately follow complex transcripts like names, addresses, time, medical terms. etc.

Enterprise Ready

Enterprise-grade reliability with 99.9% uptime, SOC2 compliance, and full on-premises support.

How they stack up

Voice Quality

In head-to-head evaluations, our blinded human tests showed that Sonic-2 was preferred over ElevenLabs's Flash V2 model by a significant margin (61.4% vs 38.6%).

Blinded human evaluation is a method where evaluators assess generative voice model outputs without knowing which model produced them, helping reduce bias. The process involves presenting outputs from different generative voice model anonymously. This approach prevents evaluators' preconceived notions about specific generative voice model or their developers from influencing their assessment.

Latency

We measure latency using the model latency and the Time to First Audio (TTFA) latency from Asia, US and Europe. We calculate the 90th percentile score (P90) from 100 measurements for each provider.

Cartesia's Sonic-2 model achieves a model latency of just 40ms—significantly faster than ElevenLabs' Flash V2 model at 75ms. P90 latency measurements across all three locations demonstrate Cartesia's consistent performance advantage over ElevenLabs. While Cartesia maintains stable latency between 128-135ms, ElevenLabs' latency fluctuates widely from 264ms to 531ms.

This superior performance comes from Cartesia's Sonic model using State Space Models (SSMs), which provide a more efficient architecture for latency optimization than the traditional transformer architecture used by ElevenLabs and other providers.

Pronunciation Accuracy

Cartesia and ElevenLabs exhibit slight differences in sentence pronunciation. Cartesia excels at accurately pronouncing challenging content, such as acronyms, phone numbers, and uncommon words, and supports the International Phonetic Alphabet (IPA) for specialized use cases, like prescription drug names in healthcare. While ElevenLabs also offers reasonably accurate pronunciation, it shows less contextual awareness.

Voice Cloning

Cartesia requires only 3 seconds of audio recording to create high-quality instant voice clones, while ElevenLabs needs 30 seconds.

Cartesia offers unlimited instant voice cloning in the paid plans, whereas ElevenLabs limits cloning in tiered plans that allow 10, 30, 160, or 660 custom voices.

Cartesia's advanced embedding technology delivers consistent, high-quality voice clones, preserving accents and voice quality even with noisy source audio. With its voice mixing and design capabilities, Cartesia creates a more comprehensive range of diverse voices. The following samples of Engelbart's clones demonstrate how Cartesia produces clearer, higher-quality clones compared to ElevenLabs.

Voice Design Controllability

Cartesia stands out as the only provider offering emotion and speed modulation features, enabling refined voice adjustments while preserving a natural and seamless auditory experience.

Cartesia also allows you to localize the voice to match different accents — you can start with an American voice and have it speak in a French accent, for instance. In comparison, ElevenLabs only offers controls for stability, similarity, and style exaggeration, all of which do not offer clear control for the voice.

In the following example where the speaker is addressing a customer complaint, we compare the dial effects from ElevenLabs and Cartesia to find that the ElevenLabs voice sounds similar with the various dials applied while Cartesia's emotion and speed dials convey very noticeable changes.

Hear the difference

Same prompts, side by side. Press play to compare Cartesia and ElevenLabs.

Voice cloning

Example with noisy background.

Cartesia better matches the original voice as well as the surrounding recording environment

ElevenLabs struggles to separate background noise from human voices, resulting in lower-quality voice clones.

Example with Reporter in Wildfire

Cartesia better preserves the accent and the surrounding recording environment

No hallucinations

For example, when pronouncing an abbreviated date like "Dec. 25, 2022," Cartesia delivers a more human-like pronunciation of "December," whereas ElevenLabs tends to interpret it more literally.

Controllability

Pricing Plans for Cartesia and ElevenLabs

Free - $0 per month with 20k free credits

Free - $0 per month with 10k characters

Pro - $5 per month with 100k credits

Starter - $5 per month with 30k characters

Startup - $49 per month with 1.25M credits

Professional - $11 per month with 100k characters

Scale - $299 per month with 8M credits

Pro - $99 per month with 500k characters

Enterprise - trusted by Fortune 500 companies

Scale - $330 per month with 2M characters

Trusted by leading enterprises. Speaking from experience.

Discover success stories

Elise AI

We didn't switch to Sonic 3.5 because it was incrementally better, we switched because nothing else came close… we've seen a 2.9% lift in our conversion and a 12.2% increase in customer engagement.

ServiceNow

Cartesia's state-space models bring enterprise-grade speed and quality to our AI Voice Agents… making it possible for businesses to deploy secure, scalable voice agents that can understand, act, and adapt in real time.

Sierra

Cartesia Sonic 3.5 has become one of the top-performing models for us by combining low latency with natural pacing… helping us deliver strong voice quality across a growing set of languages where other models often fall short.

Callers

Sonic 3.5 has been a meaningful upgrade for Callers… latency and naturalness directly impact conversational flow and user success, and the new model noticeably improves both. We've seen more human interactions — especially in high-volume customer conversations where every millisecond and every turn matters.

Take2 AI

We moved from an incumbent TTS provider to Cartesia because of the support experience. After repeated roadblocks with our previous provider, the difference with Cartesia has been transformative — responsive, technical, and genuinely invested in our success.

Elise AI

We didn't switch to Sonic 3.5 because it was incrementally better, we switched because nothing else came close… we've seen a 2.9% lift in our conversion and a 12.2% increase in customer engagement.

ServiceNow

Cartesia's state-space models bring enterprise-grade speed and quality to our AI Voice Agents… making it possible for businesses to deploy secure, scalable voice agents that can understand, act, and adapt in real time.

Sierra

Cartesia Sonic 3.5 has become one of the top-performing models for us by combining low latency with natural pacing… helping us deliver strong voice quality across a growing set of languages where other models often fall short.

Callers

Sonic 3.5 has been a meaningful upgrade for Callers… latency and naturalness directly impact conversational flow and user success, and the new model noticeably improves both. We've seen more human interactions — especially in high-volume customer conversations where every millisecond and every turn matters.

Take2 AI

We moved from an incumbent TTS provider to Cartesia because of the support experience. After repeated roadblocks with our previous provider, the difference with Cartesia has been transformative — responsive, technical, and genuinely invested in our success.

Elise AI

We didn't switch to Sonic 3.5 because it was incrementally better, we switched because nothing else came close… we've seen a 2.9% lift in our conversion and a 12.2% increase in customer engagement.

ServiceNow

Cartesia's state-space models bring enterprise-grade speed and quality to our AI Voice Agents… making it possible for businesses to deploy secure, scalable voice agents that can understand, act, and adapt in real time.

Sierra

Cartesia Sonic 3.5 has become one of the top-performing models for us by combining low latency with natural pacing… helping us deliver strong voice quality across a growing set of languages where other models often fall short.

Callers

Sonic 3.5 has been a meaningful upgrade for Callers… latency and naturalness directly impact conversational flow and user success, and the new model noticeably improves both. We've seen more human interactions — especially in high-volume customer conversations where every millisecond and every turn matters.

Take2 AI

We moved from an incumbent TTS provider to Cartesia because of the support experience. After repeated roadblocks with our previous provider, the difference with Cartesia has been transformative — responsive, technical, and genuinely invested in our success.

Elise AI

We didn't switch to Sonic 3.5 because it was incrementally better, we switched because nothing else came close… we've seen a 2.9% lift in our conversion and a 12.2% increase in customer engagement.

ServiceNow

Cartesia's state-space models bring enterprise-grade speed and quality to our AI Voice Agents… making it possible for businesses to deploy secure, scalable voice agents that can understand, act, and adapt in real time.

Sierra

Cartesia Sonic 3.5 has become one of the top-performing models for us by combining low latency with natural pacing… helping us deliver strong voice quality across a growing set of languages where other models often fall short.

Callers

Sonic 3.5 has been a meaningful upgrade for Callers… latency and naturalness directly impact conversational flow and user success, and the new model noticeably improves both. We've seen more human interactions — especially in high-volume customer conversations where every millisecond and every turn matters.

Take2 AI

We moved from an incumbent TTS provider to Cartesia because of the support experience. After repeated roadblocks with our previous provider, the difference with Cartesia has been transformative — responsive, technical, and genuinely invested in our success.

Cresta

Sonic 3.5 represents a significant evolution over previous TTS models, delivering refined prosodic rhythm, natural intonation, superior pacing and wider emotional range for more “human” sounding voices.

Bolna

Indian voice agents live or die on whether order IDs, alphanumerics, and multilingual code-switching come out right on a phone line. Sonic 3.5 handles alphanumerics natively… and lands first audio at 100ms p90.

Goodcall

Sonic is the only product in existence with model latency of less than 100 ms, outperforming its next best alternative by a factor of four. This level of performance represents a quantum leap forward.

Quora

Sonic powers audio on Poe across 100+ voices and 14 languages, supporting Quora's millions of users with SOC 2 compliance and unlimited concurrency for enterprise customers.

Fundamento

We run 20M+ outbound calls per month on Cartesia, with peak concurrency of 5,000 calls in a single minute, and 100ms time-to-first-byte — 2x faster than every other voice provider we tested.

Cresta

Sonic 3.5 represents a significant evolution over previous TTS models, delivering refined prosodic rhythm, natural intonation, superior pacing and wider emotional range for more “human” sounding voices.

Bolna

Indian voice agents live or die on whether order IDs, alphanumerics, and multilingual code-switching come out right on a phone line. Sonic 3.5 handles alphanumerics natively… and lands first audio at 100ms p90.

Goodcall

Sonic is the only product in existence with model latency of less than 100 ms, outperforming its next best alternative by a factor of four. This level of performance represents a quantum leap forward.

Quora

Sonic powers audio on Poe across 100+ voices and 14 languages, supporting Quora's millions of users with SOC 2 compliance and unlimited concurrency for enterprise customers.

Fundamento

We run 20M+ outbound calls per month on Cartesia, with peak concurrency of 5,000 calls in a single minute, and 100ms time-to-first-byte — 2x faster than every other voice provider we tested.

Cresta

Sonic 3.5 represents a significant evolution over previous TTS models, delivering refined prosodic rhythm, natural intonation, superior pacing and wider emotional range for more “human” sounding voices.

Bolna

Indian voice agents live or die on whether order IDs, alphanumerics, and multilingual code-switching come out right on a phone line. Sonic 3.5 handles alphanumerics natively… and lands first audio at 100ms p90.

Goodcall

Sonic is the only product in existence with model latency of less than 100 ms, outperforming its next best alternative by a factor of four. This level of performance represents a quantum leap forward.

Quora

Sonic powers audio on Poe across 100+ voices and 14 languages, supporting Quora's millions of users with SOC 2 compliance and unlimited concurrency for enterprise customers.

Fundamento

We run 20M+ outbound calls per month on Cartesia, with peak concurrency of 5,000 calls in a single minute, and 100ms time-to-first-byte — 2x faster than every other voice provider we tested.

Cresta

Sonic 3.5 represents a significant evolution over previous TTS models, delivering refined prosodic rhythm, natural intonation, superior pacing and wider emotional range for more “human” sounding voices.

Bolna

Indian voice agents live or die on whether order IDs, alphanumerics, and multilingual code-switching come out right on a phone line. Sonic 3.5 handles alphanumerics natively… and lands first audio at 100ms p90.

Goodcall

Sonic is the only product in existence with model latency of less than 100 ms, outperforming its next best alternative by a factor of four. This level of performance represents a quantum leap forward.

Quora

Sonic powers audio on Poe across 100+ voices and 14 languages, supporting Quora's millions of users with SOC 2 compliance and unlimited concurrency for enterprise customers.

Fundamento

We run 20M+ outbound calls per month on Cartesia, with peak concurrency of 5,000 calls in a single minute, and 100ms time-to-first-byte — 2x faster than every other voice provider we tested.

Frequently asked questions

How does voice cloning work?

What is the latency for voice generation?

Can I customize the cloned voice?

How many languages does Cartesia support?

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