Fixie AI vs Retell AI
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 →Retell AI
Low-latency voice agent platform with emotion-adaptive dialogue for sales and support
From $0.07/mo
Read full review →Side-by-side comparison
| Fixie AI | Retell AI | |
|---|---|---|
| Tagline | Developer platform for building voice AI agents that handle inbound and outbound phone calls | Low-latency voice agent platform with emotion-adaptive dialogue for sales and support |
| Pricing | Free tier | From $0.07/mo |
| Categories | voice-agents, voice, api, developer-tools | voice-agents, api, sales |
| Made by | Fixie AI | Retell AI |
| Launched | 2023-05 | 2024-04 |
| 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
Retell AI highlights
- + Sub-800ms end-to-end latency from utterance end to first audio byte
- + Emotion-adaptive dialogue that adjusts agent tone based on detected caller sentiment
- + Built-in speech-to-text and text-to-speech with no separate provider configuration needed
- + Phone number provisioning and SIP trunking for inbound and outbound calling
- + Custom LLM support via bring-your-own-endpoint configuration
Frequently Asked Questions
Which is better, Fixie AI or Retell AI?
Neither is universally better. Fixie AI (Free tier) leans into voice-agents, while Retell AI (From $0.07/mo) is closer to voice-agents. Pick based on which workflow you actually do every day.
What is the price difference between Fixie AI and Retell AI?
Fixie AI is free tier. Retell AI is from $0.07/mo. See the pricing row in the comparison table.
Can I use Fixie AI and Retell AI 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.