Real-Time Voice Agentsfreemium

Ultravox

Speech-native processing skips the STT-to-text bottleneck, preserving tone/cadence/pitch

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What Ultravox does

  • Speech-native processing skips the STT-to-text bottleneck, preserving tone/cadence/pitch
  • Free tier: 5¢/min including TTS for up to 5 concurrent calls
  • Open-weight models (fixie-ai) published on Hugging Face for research use

Ultravox — straight answers

What is Ultravox?

Ultravox is listed under Real-Time Voice Agents, in the AI Agents & Automation category on Flocci AI Tools. Speech-native processing skips the STT-to-text bottleneck, preserving tone/cadence/pitch. It is freemium — a usable free tier with paid plans above it, and it lives at ultravox.ai.

Is Ultravox free?

Ultravox is freemium: there is a free tier you can work in and paid plans above it. It is one of 391 freemium tools in the catalog, all labelled the same way so you are never surprised by a paywall.

What can Ultravox do?

Ultravox does 3 things the catalog singles out: Speech-native processing skips the stt-to-text bottleneck, preserving tone/cadence/pitch; free tier: 5¢/min including tts for up to 5 concurrent calls; open-weight models (fixie-ai) published on hugging face for research use.

What is the best free alternative to Ultravox?

LiveKit Agents is the closest free alternative: it sits in the same Real-Time Voice Agents sub-category and is free. Pipecat, Bland AI and Retell AI also start free. The full list is on the alternatives page.

See the full list →

Ultravox alternatives

Compare all alternatives →

Vapi

Real-Time Voice Agents
freemium
  • Orchestrates STT/LLM/TTS providers of choice into one low-latency voice-agent pipeline
  • Usage-based per-minute pricing with free trial minutes included
  • SOC 2/HIPAA/PCI compliance add-ons for regulated call-center deployments
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Retell AI

Real-Time Voice Agents
freemium
  • Free starting credit with no contract required
  • Supports swapping GPT, Claude or Gemini as the reasoning layer per agent
  • Batch calling campaigns plus live AI-to-human call transfer built in
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Bland AI

Real-Time Voice Agents
freemium
  • All-in-one per-minute pricing bundles LLM+STT+TTS with no separate token pass-through charges
  • Free start with call credits plus an inbound number included
  • Tiered platform fees (Build/Scale) unlock lower per-minute rates for high volume
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LiveKit Agents

Real-Time Voice Agents
free
  • Apache-2.0 open-source framework, fully self-hostable on your own servers
  • Native WebRTC client support across web/mobile/telephony out of the box
  • Native Model Context Protocol (MCP) support for tool-using voice agents
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Pipecat

Real-Time Voice Agents
free
  • BSD-2-Clause open-source Python framework for real-time voice/multimodal agents
  • Supports distributed multi-agent systems with handoffs over a shared bus
  • Maintained by Daily with an active plugin ecosystem for STT/LLM/TTS providers
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Manus

General Autonomous Agents
freemium
  • Fully autonomous agent in a cloud sandbox
  • Breaks goals into steps and executes them
  • Web research, code execution and file output
  • 'My Computer' desktop environment
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Head-to-head comparisons

Ultravox vs VapiUltravox vs Retell AIUltravox vs Bland AIUltravox vs LiveKit AgentsUltravox vs PipecatUltravox vs Manus