Cartesia vs Speechify
Discover the key differences between Cartesia and Speechify voice AI models. Learn about their features and pricing.
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Comparing Cartesia and Speechify Voice AI Models
Cartesia offers ultra-fast voice generation with a 40 ms latency, best suited for real-time interactions. Better still, its voices are ultra-realistic with no hallucinations, providing clarity and authenticity for various applications.
Updated on:
Feb 14, 2025
Features
Cartesia
40ms for the Sonic Turbo model, 90ms for the Sonic 2.0 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
Fully customizable voice with speed and emotion controls + 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
Speechify
sub-250ms
Less depth and reliability ratings in human evals
Limited character count for longer texts
Requires 20 seconds of audio
Requires several hours of voice data
IPA support, isolated pronunciation
Stability, similarity, and style exaggeration controls
8kHz audio
No on-device or on-prem support
60
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 provides high-fidelity voice cloning with unmatched accuracy and voice quality.
Ultra-Realistic Voices
Experience lifelike voices that are conversational and nearly indistinguishable from human speech.
No Hallucinations
Enjoy accurate transcription with no errors in voice generation. Handles complex transcripts well, including names, addresses, times, and more.
Enterprise Ready
Enterprise-grade reliability with 99.9% uptime, SOC2 compliance, and full on-premises support.
Voice Quality Comparison
Cartesia consistently outshines Speechify in voice quality, earning higher ratings in human evaluations for naturalness and realism. The Sonic 2.0 model achieves an impressive quality score of 4.7 out of 5 in independent evaluations—significantly above Speechify's ratings.
Latency Performance
The Cartesia Sonic model achieves impressive latency performance, with a Time to First Audio (TTFA) of just 120 ms—significantly faster than Speechify's 832 ms TTFA at the self-serve tier.
This superior speed stems from Cartesia's State Space Model (SSM) architecture, which optimizes latency better than traditional transformer designs. As a result, users enjoy near-instantaneous audio responses, making the system ideal for real-time applications.
Hallucination Rate Analysis
Cartesia's text to speech technology boasts a no hallucination feature, ensuring that the generated audio is clear and authentic. This is a significant advantage over Speechify, which may produce distorted outputs under certain conditions.
Cartesia's advanced algorithms maintain the integrity of the original transcript, providing users with accurate, reliable and high-quality voice outputs. This focus on accuracy and clarity is essential for applications where voice fidelity is paramount.
Voice Cloning Showdown
Cartesia excels at voice cloning, creating instant clones from just 3 seconds of audio. This unlimited cloning capability makes it a powerful tool for creators and developers, while Speechify requires longer 30-second audio samples and has more restrictions.
Using advanced embedding technology, Cartesia produces high-quality voice clones that preserve accents and voice characteristics, even with noisy audio. The platform's voice mixing and design features also offer a broader range of voice options.
Voice Design Controllability
Cartesia distinguishes itself through advanced voice design controls, including emotion and speed modulation. Users can make precise adjustments while maintaining natural, seamless audio quality. The platform also supports voice localization with different accents, adding to its versatility.
By comparison, Speechify provides only basic control options, prioritizing stability over the detailed customization that Cartesia offers.
Explore Pricing for Cartesia and Speechify
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
Speechify
10 standard reading voices, listen anywhere
200+ high quality voices, 60+ languages
Access to all features, priority support
Unlimited access, advanced features
Custom solutions, dedicated support
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
