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fixie.ai

Ultravox (formerly Fixie.ai) is a speech-native voice AI API for building real-time conversational voice agents.

Our take: Fixie.ai has fully rebranded to Ultravox.ai (fixie.ai now redirects there) and pivoted to speech-native voice AI infrastructure.

Best forDevelopers
ReviewedPricing: Freemium
7.2 out of 105 criteria · see breakdown
Try fixie.aiFree (30 min); Pro $100/mo
The bottom line

Developer-first voice AI infrastructure for real-time conversational agents — now operating as Ultravox.ai.

Our score

Reviewed by the Conversion Gems editorial team. Hover a facet to focus it; click to pin.Tap a facet to focus it.

What it is, and why we rate it

One line each. Open a row for detail.

What it really isUltravox (fka Fixie.ai) — speech-native voice AI API for building real-time conversational voice agents.
Our takeFixie.ai has fully rebranded to Ultravox.ai (fixie.ai now redirects there) and pivoted to speech-native voice AI infrastructure.
The product is a developer API for building low-latency real-time voice agents that process audio directly without a text-transcription step. Pricing has also changed: entry is free (30 min/mo), usage is $0.05/min after, and the only paid tier is Pro at $100/mo.
Why we rate itUltravox's speech-native architecture sidesteps the ASR bottleneck that plagues pipeline-based voice stacks.
The open-source model on HuggingFace (fixie-ai/ultravox) lets developers benchmark quality before committing API spend. The free playground and usage-based entry tier are genuinely developer-friendly for prototyping.
The catchThere is no mid-tier — it jumps from free usage to $100/mo Pro with no stepping stone.
SIP/telephony costs ($0.48/min) add up quickly for production call-center workloads, and it requires coding skill; no-code teams are out.

Best / not good for

Best for
  • Developers building real-time voice agent products
  • Startups prototyping conversational AI with telephony
  • Teams needing low-latency speech-native API infrastructure
Not good for
  • Non-technical teams expecting no-code workflow automation
  • High-volume telephony deployments sensitive to per-minute costs
  • General task-automation or API-integration use cases
Trade-offs

Friction report

Trade-offs to know before signing up.

  1. Time to value
    Fast: free tier with playground access available immediately; developers can integrate the API within hours using provided SDKs.
  2. Scale breakpoint
    SIP telephony at $0.48/min scales poorly for large call-center volumes; Enterprise pricing required but not publicly disclosed.
  3. Walled garden
    Low: core model is open-source on HuggingFace; standard REST API design means switching is feasible.
Still a fit?
If none of these block you, start on the free plan.
Try fixie.ai

Frequently Asked Questions

How can fixie.ai assist with AI-driven automation or tasks?

fixie.ai assists with AI-driven automation or tasks by enabling workflow automation, bot creation, and integration.

How does fixie.ai assist with AI automation or workflows?

fixie.ai assists with AI automation and workflows by providing tools for connecting AI models, automating tasks, and integrations.

How does fixie.ai assist with AI automation tasks?

Fixie.ai assists with AI automation tasks, enabling workflow execution, integration, and scheduling.

How does fixie.ai assist in AI automation and integration?

fixie.ai assists in AI automation and integration by connecting applications, managing workflows, and executing tasks automatically.

What is fixie.ai used for in AI automation and integration?

fixie.ai is used for AI automation and integration by connecting APIs, triggering workflows, and managing automated processes.

Alternatives

  • Step up

    ElevenLabs Conversational AI for broader voice customization and enterprise-grade support.

  • Lighter alternative

    Vapi or Bland.ai for simpler voice agent deployment with lower per-minute entry costs.

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#DeveloperTools#LLMTools#AIInfrastructure

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