LangChain vs LlamaIndex(2026)
LangChain is better for teams that need largest ecosystem. LlamaIndex is the stronger choice if best-in-class for rag. LangChain is open-source (from $0) and LlamaIndex is open-source (from $0).
Full feature breakdown, pricing details, and pros & cons below.
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LangChain
LangChain is the most widely used framework for building LLM applications with chains, agents, memory, and retrieval-augmented generation (RAG) — available in Python and JavaScript.
Starting at $0
Visit LangChainLlamaIndex
LlamaIndex is a data framework for LLM applications specializing in connecting LLMs to external data sources — with best-in-class RAG pipelines, data connectors, and indexing strategies.
Starting at $0
Visit LlamaIndexHow Do LangChain and LlamaIndex Compare on Features?
| Feature | LangChain | LlamaIndex |
|---|---|---|
| Pricing model | open-source | open-source |
| Starting price | $0 | $0 |
| Chains and agents | ✓ | — |
| RAG support | ✓ | — |
| Memory management | ✓ | — |
| Tool calling | ✓ | — |
| LangSmith (observability) | ✓ | — |
| Vector store integrations | ✓ | — |
| Python + JS | ✓ | — |
| RAG pipelines | — | ✓ |
| 100+ data connectors | — | ✓ |
| Multi-modal support | — | ✓ |
| Agents | — | ✓ |
| Query engines | — | ✓ |
| Observability | — | ✓ |
| Python + TypeScript | — | ✓ |
LangChain Pros and Cons vs LlamaIndex
LangChain
LlamaIndex
Should You Use LangChain or LlamaIndex?
Choose LangChain if…
- •Largest ecosystem
- •Best documentation
- •Rapid prototyping
Choose LlamaIndex if…
- •Best-in-class for RAG
- •Rich data connectors
- •Strong enterprise adoption