LangChain vs LlamaIndex
Two broad framework options for AI SDK & agent framework. When each fits, what it costs, who moves from one to the other, and what makers who chose it say.
Which fits you
- You need many prebuilt connectors for models, tools and data sources
Use it whenYou need many connectors and want LangGraph for stateful, multi-step agents.
Trade-offLayers of abstraction make debugging harder, and the API has changed often.
- The agent mostly retrieves and reasons over your own documents
Use it whenIngesting, indexing and querying data is the core of the product.
Trade-offLess natural for agents whose work is mostly calling external tools rather than reading data.
At a glance
| Used by | 65 makers' products · 205 open-source projects | 16 makers' products · 66 open-source projects |
|---|---|---|
| Downloads | 5.1M/wk−1% vs npm | 120.7k/wk−19% vs npm |
| Pricing | Open source and free to use; optional paid LangSmith platform for tracing, evals, and deployment. · paid from $39/seat/mo (LangSmith) | Open source and free to use; optional paid LlamaCloud managed parsing/indexing service. · paid from $50/mo (LlamaCloud) |
| Free tier | Yes | Yes |
| Open source | Yes · self-hostable | Yes · self-hostable |
What makers say
Makers on using it for AI SDK & agent framework, from Product Hunt and Starter Story interviews, each linked to the source. Products with a page of their own and fuller notes first.
We chose to integrate with LangChain as it is the leading LLM framework. We are happy that it was so straightforward to integrate with LangChain and build some use cases already.
LangChain helped us orchestrate complex reasoning, memory, and planning steps behind our AI employee. It’s the brain behind turning a conversation into a functional website.
The whole ecosystem has been a great help till now. Even though we often have to develop our own. Langsmith is one of our go to tool for tracing and evaluating.
LlamaIndex provides sufficient independent tooling for building custom AI agents. Their open-source approach and developer community made it a solid choice for our platform.
The unsung hero behind Webjourney’s AI reasoning. It makes connecting structured data, embeddings, and context feel effortless.
The flexibility is what really got us hooked. We can quickly connect our LLMs with any datasource we've thrown at LlamaIndex.
Loved and watch-outs
Themes that recur in makers' words and Hacker News comments, each linked to what it summarises.
- One interface across many model providers, so switching models, prompts and chains is cheap. PHPH 2PH 3
- A large ecosystem of document loaders, chunkers, retrievers and tool integrations for RAG and agents. PHPH 2PH 3
- LangSmith tracing and evaluation show what an agent did and where it went wrong. PHPH 2PH 3
- Frequent breaking API changes force rewrites, and coding agents trained on older versions produce messy code for it. HNHN 2HN 3
- Layers of abstraction make debugging slow, and many developers find calling model APIs or lighter libraries simpler. HNHN 2HN 3HN 4
- Its built-in patterns for subagents and deep research lag current practice, such as handing off context through a file system. HNHN 2

