Fixie AI vs Vapi
Two of the most-asked-about agents in the voice-agents space. Here's how they actually stack up.
Fixie AI
Developer platform for building voice AI agents that handle inbound and outbound phone calls
Free tier
Read full review →Vapi
Developer-focused voice AI platform for building production-grade voice agents via API
Free tier
Read full review →Side-by-side comparison
| Fixie AI | Vapi | |
|---|---|---|
| Tagline | Developer platform for building voice AI agents that handle inbound and outbound phone calls | Developer-focused voice AI platform for building production-grade voice agents via API |
| Pricing | Free tier | Free tier |
| Categories | voice-agents, voice, api, developer-tools | voice-agents, api, conversational-ai |
| Made by | Fixie AI | Vapi |
| Launched | 2023-05 | 2022 |
| Platforms | API, Web | API, Web, Phone |
| Status | active | active |
Fixie AI highlights
- + Real-time voice agents that handle phone calls with sub-second latency
- + Inbound and outbound call handling with programmable logic
- + Function calling so agents can query APIs, look up data, and take actions mid-call
- + Webhook integration for real-time event handling during conversations
- + Custom voice selection with multiple TTS providers
Vapi highlights
- + Real-time streaming voice with sub-500ms response latency on most configurations
- + Bring your own LLM: works with OpenAI, Anthropic, Groq, Together, and local models
- + Bring your own STT and TTS providers including Deepgram, ElevenLabs, and Play.ht
- + Phone number provisioning and outbound/inbound call management via API
- + Function calling and tool use for external integrations mid-conversation
Frequently Asked Questions
Which is better, Fixie AI or Vapi?
Neither is universally better. Fixie AI (Free tier) leans into voice-agents, while Vapi (Free tier) is closer to voice-agents. Pick based on which workflow you actually do every day.
What is the price difference between Fixie AI and Vapi?
Fixie AI is free tier. Vapi is free tier. See the pricing row in the comparison table.
Can I use Fixie AI and Vapi together?
In most cases, yes. They serve overlapping but distinct needs, so running them side by side is common until you decide which fits your workflow.