# Cartesia Sonic alternatives

> Looking for an alternative to Cartesia Sonic? Below are the voice agents in our index that do a similar job — open-source options are ranked by real maintained adoption (GitHub stars and recent commit activity), never by sponsorship. Cartesia Sonic is a commercial product, so the list below includes both other commercial options and open-source projects you can self-host.

Cartesia Sonic's own profile notes it may not be the right fit if you need a complete voice-agent application from this component alone. If that's you, the options below are worth comparing.

Browse on the web: https://agentsearchengine.app/alternatives/cartesia-sonic

## Commercial alternatives (alphabetical — stars don't measure commercial adoption)

- [Bland AI](https://agentsearchengine.app/agents/bland-ai) — Enterprise platform for AI phone calls that sound human. · Paid product · Platform · best for enterprises running high-volume outbound and inbound ai phone calls
  - **vs Cartesia Sonic:** Pricing model differs — Cartesia Sonic is freemium, Bland AI is a paid product.
- [Deepgram Voice Agent API](https://agentsearchengine.app/agents/deepgram-voice-agent) — A unified API for speech recognition, model orchestration and speech synthesis. · Paid product · Platform · best for developers who want a managed voice pipeline with api-level control of agent behavior and tools
  - **vs Cartesia Sonic:** Pricing model differs — Cartesia Sonic is freemium, Deepgram Voice Agent API is a paid product.
- [ElevenLabs Agents](https://agentsearchengine.app/agents/elevenlabs-agents) — Conversational voice agents powered by ElevenLabs' leading speech models. · Freemium · Platform · best for voice agents that need best-in-class speech quality and voice cloning
  - **vs Cartesia Sonic:** Best for voice agents that need best-in-class speech quality and voice cloning.
- [Retell AI](https://agentsearchengine.app/agents/retell-ai) — Build AI phone agents with configurable conversation flows and call transfers. · Paid product · Platform · best for teams configuring ai phone conversations and transfer behavior through a managed platform
  - **vs Cartesia Sonic:** Pricing model differs — Cartesia Sonic is freemium, Retell AI is a paid product.

## Open-source alternatives (ranked by adoption)

1. [xiaozhi-esp32-server](https://agentsearchengine.app/agents/xiaozhi-esp32-server) — Backend service for xiaozhi-esp32 -- helps you quickly build an ESP32 device control server. · Open source · Infrastructure · 11k★ · JavaScript · MIT · active 2 days ago
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; xiaozhi-esp32-server is open-source and self-hostable.
2. [rustpbx](https://agentsearchengine.app/agents/rustpbx) — A PBX written by rust · Open source · Infrastructure · 789★ · Rust · MIT · active 2 days ago
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; rustpbx is open-source and self-hostable.
3. [Pipecat](https://agentsearchengine.app/agents/pipecat) — Compose voice and multimodal agents with Python processing pipelines. · Open source · Framework · 16k★ · Python · BSD-2-Clause · active 2 days ago · best for python developers who want to choose the services and processing stages in a custom voice or multimodal application
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; Pipecat is open-source and self-hostable.
4. [LiveKit Agents](https://agentsearchengine.app/agents/livekit-agents) — Build voice and multimodal agents that participate in LiveKit rooms. · Open source · Framework · 14k★ · Python · Apache-2.0 · active 2 days ago · best for developers building custom voice or multimodal agents around livekit rooms and their own application logic
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; LiveKit Agents is open-source and self-hostable.
5. [ten-vad](https://agentsearchengine.app/agents/ten-vad) — Voice Activity Detector (VAD): low-latency, high-performance and lightweight · Open source · SDK / library · 2.3k★ · C · active 7 months ago
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; ten-vad is open-source and self-hostable.
6. [bailing](https://agentsearchengine.app/agents/bailing) — A GPT-4o-like voice conversation robot built from ASR+LLM+TTS, integrating strong models like DeepSeek R1 and openClaw -- a genuine personal voice assistant with latency as low as 800ms. · Open source · Agent · 1.8k★ · Python · MIT · active 5 months ago · best for experimenting with a low-latency chinese-language voice assistant on modest hardware
   - **vs Cartesia Sonic:** Cartesia Sonic is a commercial product; bailing is open-source and self-hostable.

Showing the 10 closest of 32 voice agents indexed here. Complete list: https://agentsearchengine.app/category/voice-agents

## FAQ

**What is the best alternative to Cartesia Sonic?**
It depends on whether you'd rather self-host or buy a managed product. xiaozhi-esp32-server is the most widely-adopted open-source alternative (11k GitHub stars); Bland AI is one of the commercial options. Compare the full list above on adoption, license, and pricing.

**Is there a free or open-source alternative to Cartesia Sonic?**
Yes. xiaozhi-esp32-server, rustpbx, and Pipecat are open-source voice agents you can self-host for free — you still pay for the infrastructure you run them on and any model or API usage. See the ranked open-source list above.

**How are these Cartesia Sonic alternatives ranked?**
Every product in the voice agents category is a candidate. Open-source alternatives are ranked by maintained adoption — GitHub stars plus recent commit activity — so you see what's genuinely used, not abandoned. Commercial products are listed separately and alphabetically, because stars don't measure commercial adoption. Sponsored placement is always labeled and never affects the ranking.

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Source: [Agent Search Engine](https://agentsearchengine.app) — https://agentsearchengine.app/alternatives/cartesia-sonic