head to head · open source
langchain vs llama_index
langchain has 146,562 GitHub stars, 24,508 forks, 492 open issues and last shipped today. llama_index has 52,206 stars, 8,165 forks, 770 open issues and last shipped today. langchain leads on adoption by 181% (146,562 vs 52,206 stars). langchain is written in Python under MIT; llama_index is written in Python under MIT. langchain has attracted 17% as many forks as stars, llama_index 16%. llama_index was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (agents, framework), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| langchain | llama_index | |
|---|---|---|
| GitHub stars | ★ 147K | ★ 52K |
| License | MIT | MIT |
| Written in | Python | Python |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 25K | ⑂ 8.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick langchain if
- You weight community size — 147K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick llama_index if
- You want the llama_index feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and llama_index fits your workflow better
About langchain
LangChain is an open source framework for building agents and LLM powered applications, written in Python and released under the MIT license. It lives in the AI and machine learning ecosystem, specifically among AI development platforms, and it works by chaining together interoperable components and third party integrations so that AI application development becomes simpler. The project describes itself as the agent engineering platform, and its abstractions are designed to keep applications working as the underlying technology evolves.
read the full langchain overview →
About llama_index
LlamaIndex is an MIT licensed, open source Python framework for building agentic applications — retrieval augmented generation systems, agents and multi agent workflows — on top of private documents and data, and it is aimed at AI engineers and teams who need to connect large language models to their own sources of context.
read the full llama_index overview →
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Frequently asked questions
Is langchain or llama_index more popular?
langchain has 146,562 GitHub stars and llama_index has 52,206. langchain has the larger community by that measure.
Are langchain and llama_index free?
Both are open source. langchain is licensed under MIT and llama_index under MIT. Neither carries a licence fee.
What is the difference between langchain and llama_index?
langchain is written in Python and llama_index in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, langchain or llama_index?
Choose langchain if you want the larger community (146,562 stars) or its MIT licence terms. Choose llama_index if its feature set, stack or MIT licence fits better. Both are self-hostable.