Updated February 14, 2025

Comparing Cartesia and Amazon Polly Voice Models

Q: How does voice cloning work?

Voice cloning uses advanced AI algorithms to replicate a person's voice. By analyzing audio samples, the system learns the unique characteristics of the voice, including tone, pitch, and accent. Once trained, the model can generate new speech that sounds like the original speaker. Cartesia's technology allows for cloning with just a short audio sample, making it efficient and accessible for various applications.

Q: What is the latency of Cartesia's voice model?

Cartesia's Sonic model achieves an impressive latency of 135ms, which is significantly lower than many competitors. This low latency ensures that users experience seamless interactions, making it ideal for real-time applications such as customer support and gaming. The efficiency of the model is attributed to its innovative architecture, which optimizes performance without compromising quality.

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 developers and content creators to tailor the voice output to suit specific needs and contexts, enhancing the overall user experience. The ability to localize voices to different accents further adds to the customization options available.

Q: What languages does Cartesia support?

Cartesia supports seamless speech in 13 languages, including English, Spanish, French, German, Japanese, and more. This multilingual capability allows users to reach a global audience and create content that is accessible to diverse populations. The platform is continually updated to include additional languages, ensuring broad coverage for various applications.

Comparing Cartesia and Amazon Polly Voice Models. Discover the differences in features, pricing, and performance.

Try Cartesia Talk to Sales

Comparing Cartesia and Amazon Polly Voice Models

Cartesia offers ultra-fast voice generation at 40ms latency, ultra-realistic voices with no hallucinations, and infinite character limits. In contrast, the other option has a higher latency and limited character requests.

Latency

40ms for the Sonic Turbo model, 90ms for the Sonic 2 model

100ms – 500ms + network time

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 character count for longer texts

Instant Cloning

Requires 3 seconds of audio

Not supported

Professional Voice Cloning

Requires 30 minutes of audio

Not supported

Pronunciation Accuracy

IPA support with strong contextual understanding

IPA support, isolated pronunciation

Voice Customizations

Slider control for speed and emotion + synthetic voice mixing and design

Stability, similarity, and style exaggeration controls

Telephony Optimization

8kHz audio, telephony optimized voices

8kHz audio

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 18 concurrent

Latency

Cartesia 40ms for the Sonic Turbo model, 90ms for the Sonic 2 model

Amazon Polly 100ms – 500ms + network time

Voice Quality

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

Amazon Polly Less depth and reliability ratings in human evals

Character Limits

Cartesia Infinite request length

Amazon Polly Limited character count for longer texts

Instant Cloning

Cartesia Requires 3 seconds of audio

Amazon Polly Not supported

Professional Voice Cloning

Cartesia Requires 30 minutes of audio

Amazon Polly Not supported

Pronunciation Accuracy

Cartesia IPA support with strong contextual understanding

Amazon Polly IPA support, isolated pronunciation

Voice Customizations

Cartesia Slider control for speed and emotion + synthetic voice mixing and design

Amazon Polly Stability, similarity, and style exaggeration controls

Telephony Optimization

Cartesia 8kHz audio, telephony optimized voices

Amazon Polly 8kHz audio

Flexible deployments

Cartesia Supports both on-prem and on-device deployments

Amazon Polly No on-device or on-prem support

Languages Supported

Cartesia 15 languages with extensive dialect coverage

Amazon Polly 29

Concurrency

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

Amazon Polly Up to 18 concurrent

Cartesia - Advanced AI Voice Capabilities

Low Latency Performance

Cartesia's Sonic model boasts a low latency of 135ms, ensuring real-time interactions.

High-Quality Voice Cloning

Instantly clone voices with just 3 seconds of audio, delivering high-fidelity results.

Ultra-Realistic Voices

Cartesia provides lifelike voices that are nearly indistinguishable from human speech.

Enterprise Ready

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

How they stack up

Voice Quality Comparison

In evaluating voice quality, Cartesia consistently outperforms Amazon Polly. Cartesia's Sonic model has received a score of 4.7 in independent evaluations, while Amazon Polly scored 4.38. This difference highlights Cartesia's superior naturalness and emotional sensitivity in voice output. Furthermore, Cartesia's voices are designed to be nearly indistinguishable from human speech, providing a more engaging experience for users. This commitment to quality makes Cartesia a preferred choice for applications requiring lifelike voice interactions.

Latency Performance Test

Latency is crucial for real-time applications. Cartesia measures latency using the Time to First Audio (TTFA) metric, achieving a remarkable TTFA of 199 ms. In comparison, Amazon Polly's latency is significantly higher, at 300 ms. This efficiency is due to Cartesia's innovative State Space Models (SSMs), which optimize performance far beyond traditional transformer architectures. The low latency of Cartesia's Sonic model ensures that users experience seamless interactions, making it ideal for applications like customer support and gaming.

Hallucination Rate Analysis

Cartesia stands out with its no hallucination feature, ensuring that voice outputs are accurate and authentic. This is achieved through advanced AI voice cloning technology that eliminates errors and maintains clarity. In contrast, Amazon Polly may experience occasional inaccuracies in voice generation. Cartesia's commitment to delivering crystal-clear audio enhances user trust and satisfaction, making it a reliable choice for applications that require high fidelity in voice outputs.

Voice Cloning Showdown

When it comes to voice cloning, Cartesia excels with its ability to create an instant clone from just 3 seconds of audio. In contrast, Amazon Polly has restrictions on cloning capabilities, requiring longer audio samples. Cartesia's advanced embedding technology ensures high-quality voice replication, maintaining accents and voice quality even in noisy conditions. Additionally, Cartesia's voice mixing and design features provide a wider variety of voices, making it a superior choice for diverse applications.

Voice Design Controllability

Cartesia offers unique voice design controllability features, including emotion and speed modulation, allowing users to create refined voice adjustments that sound natural. This capability enables users to localize voices to match different accents, enhancing the overall user experience. In contrast, Amazon Polly provides limited control options, focusing mainly on stability and similarity without the nuanced adjustments available in Cartesia's offerings. This flexibility makes Cartesia a more versatile tool for developers and content creators.

Pricing Comparison for Cartesia and Amazon Polly

Free - $0 per month with 20k free credits

Standard voices priced at $4.00 per 1 million characters

Pro - $5 per month with 100k credits

Neural voices priced at $16.00 per 1 million characters

Startup - $49 per month with 1.25M credits

Long-Form voices priced at $100.00 per 1 million characters

Scale - $299 per month with 8M credits

Generative voices priced at $30 per 1 million characters

Enterprise - trusted by Fortune 500 companies

Custom pricing based on usage and requirements

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 of Cartesia's voice model?

Can I customize the cloned voice?

What languages does Cartesia support?

Architecting AI that learns and interacts like humans.

Products

Company

Resources

Solutions

Capabilities

Products

Solutions

Capabilities

Resources

Company