Cartesia vs Google
Cartesia rates higher than every Gemini TTS model, and generates speech faster.
ServiceNow, Decagon, and Quora run their production voice agents on Cartesia, with first audio in under 90ms.
Voice quality
Cartesia rates higher than every Gemini TTS model
- The Provider Voice Arena rates every model on its own voices, so a voice roster counts alongside the model that speaks it.
- Google sells its text to speech on lifelike voices. On a blind listening test, Sonic 3.6 rates first of the 90 models on the board, above Gemini 3.1 Flash TTS and every earlier Gemini TTS model.
Provider Voice Arena Elo
Higher is better
Speed
Cartesia generates about five times as fast as Google's best-rated model
- Artificial Analysis times generation for every model on the board, so both sides run through the same harness.
- Generating well ahead of playback is what keeps a long turn from stalling mid-sentence. Of the two Gemini TTS models Artificial Analysis has timed, the one it rates highest for quality is the slower.
Characters per second
Higher is better
Reasons why companies choose Cartesia over Gemini TTS
Human-like naturalness
Intonation, pacing, pronunciation, emotion, and audio quality that drive higher completion rates
Cartesia1275 EloGemini TTS1202 EloGemini 3.1 Flash TTS1077 EloGemini 2.5 Flash Lite TTS1049 EloGemini 2.5 Flash TTSSeptember 2026
Model maturity
Whether the model you benchmark is the model you can ship on.
CartesiaSonic 3.6 is the default model on the public APIGemini TTSAll three Gemini TTS models Google documents are preview releasesCustom voices
How much audio it takes, and who is allowed to use one.
CartesiaInstant clone from 10 seconds, professional clone from 30 minutes, on the public APIGemini TTSGemini TTS has 30 prebuilt voices and no cloning. Cloud Text-to-Speech cloning is restricted to allow-listed users, through sales.Streaming
Whether audio starts playing before the whole turn has been generated.
CartesiaEvery Sonic model streamsGemini TTSStreaming starts at Gemini 3.1. The earlier Gemini TTS models return the finished clip.Deployment
Decides whether regulated teams can use it at all.
CartesiaVPC, on-prem, on-device, or air-gapped, behind a 99.9% uptime SLAGemini TTSGoogle Cloud, Vertex AI, and the Gemini API
Frequently asked questions
Which Google models does this compare against?
Gemini 3.1 Flash TTS, Gemini 2.5 Flash Lite TTS, and Gemini 2.5 Flash TTS, which is how Artificial Analysis lists Google's Gemini text to speech models. Google's own IDs for the models it documents are gemini-3.1-flash-tts-preview, gemini-2.5-flash-preview-tts, and gemini-2.5-pro-preview-tts. Artificial Analysis has timed generation speed for two of them, so Gemini 2.5 Flash Lite TTS appears on the quality chart and not the speed chart.
What about Google Cloud Text-to-Speech?
Google sells an older set of Cloud Text-to-Speech voices alongside Gemini TTS: Chirp 3: HD, Studio, Journey, Neural2, WaveNet, and Standard. Artificial Analysis rates all of them, and rates every one below Gemini 3.1 Flash TTS. Cloud Text-to-Speech is also where Google's voice cloning lives, as Chirp 3: Instant Custom Voice, which their documentation says is restricted to allow-listed users.
How is the quality score measured?
It comes from Artificial Analysis, an independent benchmark. Listeners hear two clips of the same line without being told which model produced either, and pick the one they prefer. The Provider Voice Arena lets every model speak in its own voices. Cartesia's Sonic 3.6 also ranks first on their Controlled Voice Arena, which gives every model the same set of cloned voices.
Can I use my own voice with Cartesia?
Yes. An instant clone takes 10 seconds of audio and a professional clone takes 30 minutes. Both are on the public API, rather than reserved for an enterprise agreement.
Can I run Cartesia on my own infrastructure?
Yes. Cartesia deploys on-prem and air-gapped, which teams in healthcare, finance, and government use to keep audio inside their own network, backed by a 99.9% uptime SLA.
How long does it take to switch from Gemini TTS?
One to two weeks for most teams. Cartesia is integrated into the major voice agent platforms and every model is on the public API, so there is no platform to move onto and nothing to unpick later.
Get started today
Talk to an expert.
Connect with a member of our team and learn how Cartesia can help you build world-class voice experiences.
Start building.
Access our models via API and bring a voice agent into production in minutes.