Compare Cartesia and ElevenLabs Voice AI Models

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.

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.

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.

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.

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.