ElevenLabs vs Cartesia vs Vapi
Three voice AI tools for different jobs — voice generation, low-latency TTS, and turnkey phone agents.
ElevenLabs, Cartesia, and Vapi are three voice AI products that solve adjacent but distinct problems. ElevenLabs is the consumer-and-developer voice generation leader — voice cloning, dubbing, audiobooks, character voices, with a vast library of voices and the most polished creator-facing app. Cartesia is the low-latency real-time voice infrastructure play — the Sonic family of TTS models is built for sub-100ms inference, optimized for live agents and conversational AI. Vapi is the turnkey voice-agent platform — it stitches together speech-to-text, LLM, and text-to-speech into a phone agent you can deploy by configuring a few JSON blocks instead of building a stack from scratch. The relationship between them: many production voice agents use Vapi as the orchestration layer, plugging in Cartesia for the lowest-latency TTS and/or ElevenLabs for the best voice quality, with the LLM layer being whatever you want (GPT, Claude, Gemini). They're more often complements than competitors. This page covers when each one wins as the primary choice.
Quick verdict — which one for which task
Feature comparison
| Feature | ElevenLabs | Cartesia | Vapi |
|---|---|---|---|
| Pricing (entry) | Free 10k chars/mo; Starter $5/mo; Creator $22/mo; Pro $99/mo | Free tier; usage-based pricing for production (per-character TTS) | Free trial credits; pay-per-minute usage (~$0.05–0.15/min depending on stack) |
| Primary product type | Voice generation, cloning, dubbing — creator + API | Low-latency TTS API (Sonic models) — infrastructure | Voice agent orchestration platform — turnkey |
| Telephony (phone numbers) | Conversational AI tier provides telephony | TTS only — bring your own telephony (Twilio, etc.) | Native — provision and manage phone numbers in-platform |
| Voice cloning | Best-in-class — Instant Voice Clone + Professional Voice Clone | Voice cloning supported — focused on production use | Inherits whichever TTS provider you plug in |
| Latency (TTS first-byte) | Turbo / Flash models bring it under ~150ms; Multilingual is higher | Best-in-class — Sonic models target ~75–100ms first-byte | Depends on TTS choice — Cartesia/ElevenLabs Flash both supported |
| Languages supported | 30+ languages with strong quality across most | Multiple languages, expanding; English is most mature | Inherits from underlying TTS; multilingual via ElevenLabs/Cartesia |
| Best at | Content creation — audiobooks, podcasts, dubbing, character voices |
Benchmarks
Public benchmark scores. Numbers shift between model releases — verify against the latest sources before quoting.
Pros and cons by tool
Bottom line
ElevenLabs, Cartesia, and Vapi solve overlapping but distinct voice-AI problems and are often used together in production stacks. Many users subscribe to multiple — here's which task each wins: voice cloning, audiobooks, dubbing, and creator content go to ElevenLabs, lowest-latency real-time TTS for live agents goes to Cartesia, turnkey phone agent shipping goes to Vapi. A common production stack is Vapi as the orchestrator with Cartesia as the TTS for latency-sensitive live calls and ElevenLabs swapped in for higher-quality character voices when the use case demands it. Pick by the layer you most need to solve: content gen → ElevenLabs, infrastructure-grade TTS → Cartesia, end-to-end agent → Vapi.
Frequently asked questions
Should I use Vapi or build my own voice agent?
Vapi if you need to ship in days and your use case fits standard phone-agent patterns (appointment booking, lead qualification, customer support triage). Build your own if you need tight control over latency, flow, or branding — typical stack is Cartesia for TTS, Deepgram for STT, GPT/Claude for the LLM layer, and Twilio for telephony, orchestrated by code you write yourself.
Can I use ElevenLabs voices inside Vapi?
Yes — Vapi supports ElevenLabs as a TTS provider option. You'll typically pay both Vapi's per-minute rate and pass-through ElevenLabs character costs. Many production voice agents pick Cartesia inside Vapi for latency and use ElevenLabs only for higher-fidelity character voices when needed.
Is voice cloning legal?
Yes with proper consent and disclosure. ElevenLabs requires verified consent for Professional Voice Clone, and most jurisdictions treat unconsented voice cloning as a form of identity fraud. Don't clone anyone's voice without explicit written consent for the specific use case.
What about OpenAI's voice mode and Realtime API — should I evaluate that too?
Yes if you're building voice features inside an OpenAI-centric stack. The Realtime API gives you GPT + voice in a single bidirectional stream, which simplifies the architecture. The trade-off is latency and TTS quality — Cartesia + ElevenLabs both have edges. For existing OpenAI-API customers, Realtime is worth comparing; for cross-vendor flexibility, Vapi or a custom stack remains more flexible.
Which one for an outbound sales agent making 1000 calls/day?
Vapi if you want it shipped this week and don't want to manage telephony/LLM/TTS individually. A custom stack (Twilio + Cartesia + your LLM) if you want lower per-minute cost at scale and have engineering capacity. Either way, plan for monitoring, recording compliance, and human-handoff escalation.