Question 1

Is LlamaIndex better than Letta?

Accepted Answer

It depends on your use case. LlamaIndex is known for Data framework for connecting LLMs to external data, while Letta Build stateful AI agents with long-term memory. See our full comparison above for a detailed breakdown.

Question 2

Is LlamaIndex free?

Accepted Answer

LlamaIndex pricing: Free (open-source) + Cloud.

Question 3

Is Letta free?

Accepted Answer

Letta pricing: Free (open-source) + Cloud.

Question 4

What are the main differences between LlamaIndex and Letta?

Accepted Answer

LlamaIndex and Letta differ in features, pricing, and platform support. LlamaIndex: Data framework for connecting LLMs to external data. Letta: Build stateful AI agents with long-term memory. See the full side-by-side comparison above for details.

Feature	LlamaIndex	Letta
Category	Data & ETL	AI Agent Frameworks
Pricing	Free (open-source) + Cloud	Free (open-source) + Cloud
GitHub Stars	✓ More stars 38k	13k
Platforms	Linux, macOS, Windows	Linux, macOS, Docker
Key Features	✓ RAG pipelines ✓ Data connectors ✓ Indexing ✓ Query engine ✓ Agent tools	✓ Long-term memory ✓ Stateful agents ✓ Tool use ✓ Multi-model ✓ Self-editing memory
Pros	+ Best-in-class RAG framework + 100+ data connectors + Multiple index types + Great documentation + Active community	+ Solves long-term memory problem + Self-editing memory + Stateful agents + Multi-model support + Active research backing
Cons	− Can be complex for simple use cases − Abstractions hide complexity − Learning curve for advanced features − Some features require LlamaCloud	− Complex memory management − Performance overhead − Rebranding confusion − Still experimental
Tags	ragdataindexingopen-source	memorystatefulagentsopen-source

LlamaIndexvsLetta

LlamaIndex

Letta

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