Ultravox vs Letta
A detailed comparison to help you choose between Ultravox and Letta.
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How to choose
Neither tool has user reviews on ToolSpotter yet, so we don't pick a winner. Compare them on what they're built for: Ultravox — Teams deploying AI agents connected to internal data; Letta — Developers building stateful AI agents that need memory persistence, tool integration, and production deployment capabilities..
Ultravox Real-time, speech-native voice AI | Letta Stateful AI agent framework with memory and tool integration | |
|---|---|---|
| Rating | Not yet rated | Not yet rated |
| Pricing Model | paid | freemium |
| Starting Price | From $49/mo | Free tier available |
| Best For | Teams deploying AI agents connected to internal data | Developers building stateful AI agents that need memory persistence, tool integration, and production deployment capabilities. |
| Free Tier | ||
| API Access | ||
| Team Features | ||
| Open Source | ||
| Tags | team featuresapi access | free tieropen sourceapi access |
| Visit Ultravox → | Visit Letta → |
Ultravox
Pros
- + Easy tool integrations
- + Team workspace
- + Good documentation
Cons
- - No free tier
- - US-focused infrastructure
Letta
Pros
- + Manage persistent agent memory with structured schemas
- + Integrate external tools and APIs into agent workflows
- + Deploy locally or use managed hosting
- + Open-source with active development community
Cons
- - Steeper learning curve compared to simple LLM APIs
- - Requires familiarity with agent architecture concepts
Frequently Asked Questions
Which is better, Ultravox or Letta?▼
It depends on your specific needs — neither tool has user reviews on ToolSpotter yet, so we don't rank one above the other. Ultravox is best for: Teams deploying AI agents connected to internal data. Letta is best for: Developers building stateful AI agents that need memory persistence, tool integration, and production deployment capabilities..
What is the difference between Ultravox and Letta?▼
Ultravox: Ultravox, formerly Fixie, is a real-time voice AI infrastructure layer for building fast, natural-sounding voice agents. Letta: Letta is a framework for building stateful AI agents that keep long-term memory across sessions rather than starting each conversation fresh.
Is Ultravox or Letta more affordable?▼
Ultravox starts at €49/mo, Letta starts at €0/mo. Check the comparison table above for current pricing.
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