Cartesia vs WellSaid
Discover the key differences between Cartesia and WellSaid voice AI models. Explore features, pricing, and performance metrics.
VS
Compare Cartesia and WellSaid Voice AI Models
Both platforms offer advanced voice AI capabilities, but Cartesia excels with ultra-fast voice generation and lifelike quality, ensuring no hallucinations. With a latency of just 40ms, it outperforms many competitors in real-time applications.
Updated on:
Feb 14, 2025
Features
Cartesia
40ms for the Sonic Turbo model, 90ms for the Sonic 2 model
Consistently rated as more natural, expressive, and realistic in blinded human evaluations
Infinite request length
Requires 3 seconds of audio
IPA support with strong contextual understanding
Slider control for speed and emotion + synthetic voice mixing and design
8kHz audio, telephony optimized voices
Supports both on-prem and on-device deployments
15 languages with extensive dialect coverage
Up to 15 on highest self-serve tier (60 parallel conversations), custom for enterprise
WellSaid
Higher latency, impacting responsiveness
Others may lack the same depth and reliability.
Limited character count for longer texts
Not supported
Not supported
Some may show less contextual awareness.
Others may not offer the same level of control.
Some may not be optimized for telephony.
Limited on-device capabilities elsewhere.
20
Limited concurrent usage options
Cartesia - Advanced AI Voice Capabilities
Cartesia AI offers the fastest voice model with hallucination-free, ultra-realistic voice generation and cloning.
High-Quality Voice Cloning
Cartesia offers high-quality voice cloning with unmatched accuracy.
Ultra-Realistic Voices
Experience lifelike voices that are nearly indistinguishable from human speech.
No Hallucinations
Cartesia ensures crystal-clear audio with no distortions or errors.
Enterprise Ready
Enterprise-grade reliability with 99.9% uptime, SOC2 compliance, and full on-premises support.
Voice Quality Evaluation
In terms of voice quality, Cartesia consistently outperforms WellSaid. Cartesia's Sonic model has been rated highly in independent evaluations, achieving a score of 4.7 out of 5 for overall quality. This is significantly higher than WellSaid's score of 4.38. Cartesia's voices are recognized for their naturalness and emotional sensitivity, making them ideal for real-time applications. Furthermore, Cartesia's architecture allows for better contextual understanding, resulting in clearer and more engaging audio outputs.
Latency Performance Review
Latency is a critical factor in voice AI applications. Cartesia measures latency using the Time to First Audio (TTFA) metric, achieving an impressive TTFA of 199 ms. This is significantly faster than WellSaid, which has a TTFA of 832 ms. Cartesia's Sonic model is built on State Space Models (SSMs), allowing for greater latency optimization compared to traditional transformer architectures. This efficiency ensures that Cartesia can deliver real-time responses, enhancing user experience in conversational AI applications.
Hallucination Rate Analysis
Cartesia's voice cloning technology boasts a no hallucination feature, ensuring that the generated audio is clear and authentic. This is a significant advantage over WellSaid, which may experience occasional distortions in voice outputs. Cartesia's advanced algorithms eliminate errors and maintain the integrity of the original voice, providing users with high-fidelity audio. This reliability is crucial for applications in healthcare and customer support, where clarity and accuracy are paramount.
Voice Cloning Comparison
When it comes to voice cloning, Cartesia excels with its ability to create an instant clone from just 3 seconds of audio. This feature allows for unlimited instant voice cloning, making it a powerful tool for developers. In contrast, WellSaid restricts cloning capabilities, requiring longer audio samples. Cartesia's advanced embedding technology ensures high-quality voice clones that maintain accents and voice quality, even in noisy conditions. Additionally, Cartesia offers voice mixing and design capabilities, providing a diverse range of voices for various applications.
Voice Design Controllability
Cartesia stands out in voice design controllability, offering unique features such as emotion and speed modulation. This allows users to make refined voice adjustments while maintaining a natural sound. Additionally, Cartesia enables localization, allowing voices to adapt to different accents seamlessly. In contrast, WellSaid provides limited control options, focusing primarily on stability and similarity without the nuanced adjustments available in Cartesia's offerings.
Explore Pricing for Cartesia and WellSaid
Cartesia
Free - $0 per month with 10k free credits
Pro - $5 per month with 100k credits
Startup - $49 per month with 1.25M credits
Scale - $299 per month with 8M credits
Enterprise - trusted by Fortune 500 companies
WellSaid
Includes basic features and limited usage.
Offers additional features and higher limits.
Ideal for growing businesses with more needs.
Designed for larger enterprises with extensive usage.
Custom pricing and features for large organizations.
What Cartesia Customers Say
Join the growing list of companies opting for Sonic.
"Cartesia’s voice API power dynamic and empathetic conversational experiences that are consistently dependable. What really stands out to me is how natural and considerate the responses feel—especially the empathetic tone in statements like ‘I’m sorry, that must be frustrating.’"
Sami Ghoche, CEO of Forethought
"In 1999, Salesforce brought software to the cloud. In 2025, 11x is killing software as we know it and unleashing the era of digital workers. To realise this vision, we needed AI voice technology that feels truly human. Cartesia’s technology gives our AI digital workers reps the speed, reliability, and natural expressiveness required to engage customers at scale.
It's the only solution fit for our relentless drive toward innovation.”
Keith Fearon, Head of Product & Growth, 11x
"Before conversational voice models like Cartesia, Thoughtly relied on legacy text-to-speech APIs from major cloud providers. Nearly two years later, the evolution of this technology is staggering—customers can clone their voice and hear it speaking autonomously over the phone in just 60 seconds.”
Torrey Leonard, CEO, Thoughtly
