AI Tool Comparison
LangChain vs LlamaIndex
A side-by-side breakdown to help you pick the right tool for your workflow.
LangChain
Assemble LLM-powered apps and agents from composable building blocks, with LangSmith adding tracing, evaluation, and deployment. Platform rebranded. LangGraph Platform is now LangSmith Deployment.
LlamaIndex
Connect your own data to LLMs for retrieval-augmented generation. LlamaParse (formerly LlamaCloud) automates document parsing, extraction, and indexing for agentic workflows.
Bottom Line
Last reviewed: August 2026
LangChain and LlamaIndex both compete in Developer Tools, overlapping most directly on developer Tools. Both carry the same 4.4 rating, so the decision comes down to fit, not quality.
Choose LangChain if…
Best for developers building custom applications on top of large language models, and its edge is composable chains, agents, and memory abstractions that cut LLM app code from hundreds of lines to dozens. The standard starting framework for LLM app development, expect the API to keep shifting under you.
Choose LlamaIndex if…
Best for developers building retrieval-augmented generation apps that need to query private or enterprise data, and its edge is a wide library of data connectors that ingest PDFs, wikis, and databases into a queryable index. The strongest RAG-specific framework available, expect real overlap and some redundant decisions against LangChain.
| Attribute | LangChain | LlamaIndex |
|---|---|---|
| Category | Developer Tools | Developer Tools |
| Pricing | freemium | freemium |
| Pricing Detail | Free (5K traces) / $39/seat/mo Plus / Enterprise custom | Free (10K credits) / $5,000/mo Starter cap / Pro custom |
| Rating |
Key Features
LangChain
- Chains and agents
- Retrieval (RAG) primitives
- Memory and tool integrations
- LangSmith observability
LlamaIndex
- Data ingestion and indexing
- Advanced retrieval and query engines
- Agents and workflows
- LlamaCloud and LlamaParse
Pros
LangChain
- •Huge integration ecosystem
- •Rapid prototyping
- •Strong community
LlamaIndex
- •Best-in-class for RAG
- •Many data connectors
- •Good query abstractions
Cons
LangChain
- Abstractions can be heavy
- Frequent API changes
LlamaIndex
- Overlaps with LangChain
- Learning curve for advanced features