Fixie

AI Developer Platforms

Fixie, founded in 2022 by former engineering leaders from Apple and Google including CEO Matt Welsh, has pivoted from its original enterprise LLM platform to focus entirely on voice AI under the product name Ultravox.

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Fixie builds speech-native AI models and managed infrastructure for developers to create real-time voice agents that can understand tone, cadence, and other paralinguistic cues without transcribing speech to text first.

Fixie, founded in 2022 by former engineering leaders from Apple and Google including CEO Matt Welsh, has pivoted from its original enterprise LLM platform to focus entirely on voice AI under the product name Ultravox. The company now describes itself as a research lab and product company building speech-native AI models and infrastructure for real-time voice agents. Fixie raised a $17 million seed round in March 2023, led by Madrona Ventures, with participation from Greylock and others, as reported by TechCrunch.

The company's core offering is Ultravox v0.7, a speech model that scores 91.8% on Big Bench Audio without reasoning and 97% with thinking enabled, according to its website. Fixie also offers UltraVAD v0.1, a neural voice activity detection model for turn-taking. The company operates a managed inference stack and owns its infrastructure to minimize latency.

Pricing starts at $0.05 per minute for up to five concurrent calls, with a $100/month Pro tier and custom Enterprise pricing. As of June 2026, Fixie has not disclosed revenue or headcount publicly. The company's website lists customers including 11x, though no other named clients appear in public sources.

Fixie has committed to open science, releasing its models on Hugging Face under the handle fixie-ai. The company faces a competitive landscape dominated by OpenAI's Realtime API, Google's Gemini Live, and Anthropic's Claude Sonnet, as well as well-funded rivals like ElevenLabs and Cartesia. Fixie's pivot from LLM orchestration to voice AI represents a strategic bet that speech-native architectures will outperform cascaded speech-to-text-to-LLM pipelines, a thesis that remains unproven at scale.

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Products by Fixie

Who buys this

  • Developers building voice agents for customer support, sales, and telephony applications
  • Startups and scale-ups needing low-latency voice AI without managing inference infrastructure
  • Enterprises deploying conversational AI for contact centers and virtual assistants
  • Voice application developers on web and mobile platforms using SDKs

Strengths and what to watch

Strengths

  • Speech-native model architecture that processes paralinguistic cues (tone, cadence, pitch) directly, avoiding latency and information loss from cascaded speech-to-text pipelines
  • Open science approach with publicly available model weights on Hugging Face, which may attract developer trust and community contributions
  • Managed end-to-end inference stack gives the company control over latency and performance, differentiating from competitors that rely on third-party LLM APIs

Watch for

  • No publicly disclosed revenue, headcount, or customer count makes it impossible to assess traction or unit economics; the company is pre-revenue or early-revenue with no public metrics
  • Extremely competitive market with well-capitalized rivals including OpenAI (Realtime API), Google (Gemini Live), Anthropic (Claude Sonnet), ElevenLabs, and Cartesia; differentiation on latency and paralinguistic accuracy is narrow and hard to sustain
  • The pivot from LLM orchestration platform to voice AI in under two years suggests the original product thesis did not gain traction; investors may question strategic consistency and execution risk

Key Information

Industry
AI Developer Platforms
Founded
2022

Frequently Asked Questions

What is Fixie and what does it do?

Fixie builds speech-native AI models and managed infrastructure for developers to create real-time voice agents. Founded in 2022 by former Apple and Google engineers, it now focuses on its Ultravox product, which processes tone and cadence without transcribing speech to text first.

How does Fixie's Ultravox voice AI work?

Ultravox uses a speech-native architecture that understands paralinguistic cues like tone and cadence directly, avoiding the latency and information loss of cascaded speech-to-text pipelines. It scores 91.8% on Big Bench Audio without reasoning and 97% with thinking enabled, according to Fixie's website.

What is Fixie's pricing for voice AI?

Fixie's pricing starts at $0.05 per minute for up to five concurrent calls. A $100 per month Pro tier is available, and Enterprise plans offer custom pricing. The company owns its inference infrastructure to minimize latency for real-time voice agents.

Who are Fixie's main competitors in voice AI?

Fixie competes with OpenAI's Realtime API, Google's Gemini Live, and Anthropic's Claude Sonnet, as well as well-funded rivals like ElevenLabs and Cartesia. The market is extremely competitive, and differentiation on latency and paralinguistic accuracy is narrow and hard to sustain.

Does Fixie offer open source voice AI models?

Yes, Fixie has committed to open science and releases its models on Hugging Face under the handle fixie-ai. This includes Ultravox v0.7 and UltraVAD v0.1, a neural voice activity detection model. The approach may attract developer trust and community contributions.

What traction has Fixie shown since its pivot to voice AI?

Fixie has not publicly disclosed revenue, headcount, or customer count as of June 2026, making traction hard to assess. Its website lists 11x as a customer, but no other named clients appear in public sources. The pivot from an LLM platform to voice AI occurred in under two years.

Sources

  1. www.fixie.ai — Product description, Ultravox v0.7 benchmark scores, pricing tiers, customer logos, open science commitment, and company positioning as a research lab and product company
  2. techcrunch.com — Founding team background (Matt Welsh, former Apple and Google engineering heads), $17 million seed round led by Madrona Ventures, original product positioning as an LLM platform
  3. huggingface.co — Fixie's open model releases on Hugging Face under the fixie-ai organization
  4. www.ultravox.ai — Pricing details: $0.05/minute, $100/month Pro tier, and Enterprise custom pricing