Letta vs LlamaIndex
Updated June 2026 · A structured head-to-head comparison.
Data framework for LLM applications.
The verdict
Both Letta and LlamaIndex are credible ai agents tools, and the right pick comes down to your priorities.
Letta — Framework for stateful AI agents with memory.
LlamaIndex — Data framework for LLM applications.
Letta vs LlamaIndex: side by side
| Dimension | Letta | LlamaIndex |
|---|---|---|
| Starting price | Free | Free |
| Free plan | Yes | Yes |
| Pricing model | Open source | Open source |
| Best for | Developers, Ai Engineers | Developers, Ai Engineers |
| Platforms | Self Hosted, Api, Web | Self Hosted, Api, Web |
| Rating | 4.4/5 | 4.6/5 |
Letta key facts
- Vendor
- Letta
- Pricing
- Open source — Free
- Free tier
- Yes
- Platforms
- Self Hosted, Api, Web
- Best for
- Developers, Ai Engineers
- Editor rating
- 4.4 / 5
- Founded
- 2023
- Headquarters
- San Francisco, CA, USA
LlamaIndex key facts
- Vendor
- LlamaIndex
- Pricing
- Open source — Free
- Free tier
- Yes
- Platforms
- Self Hosted, Api, Web
- Best for
- Developers, Ai Engineers
- Editor rating
- 4.6 / 5
- Founded
- 2022
- Headquarters
- San Francisco, CA, USA
Frequently asked questions
Is Letta better than LlamaIndex?
Neither is universally better — LlamaIndex edges ahead on overall rating, but the best choice depends on price, platforms, and your use case. See the side-by-side table above.
Is Letta or LlamaIndex cheaper?
Letta is the more affordable of the two to get started, at free. Letta starts at free; LlamaIndex starts at free.
Can Letta replace LlamaIndex?
Yes for most teams — both are ai agents tools with heavily overlapping features. The main trade-offs are pricing and platform support, covered in the comparison above.