head to head · open source
llama_index vs LangWatch
llama_index has 52,202 GitHub stars, 8,162 forks, 770 open issues and last shipped yesterday. LangWatch has 4,810 stars, 393 forks, 939 open issues and last shipped yesterday. llama_index leads on adoption by 985% (52,202 vs 4,810 stars). llama_index is written in Python under MIT; LangWatch is written in TypeScript under Apache-2.0. llama_index has attracted 16% as many forks as stars, LangWatch 8%. LangWatch was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (llm), 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
| llama_index | LangWatch | |
|---|---|---|
| GitHub stars | ★ 52K | ★ 4.8K |
| License | MIT | Apache-2.0 |
| Written in | Python | TypeScript |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 8.2K | ⑂ 393 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick llama_index if
- You weight community size — 52K stars and counting
- You want the MIT license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick LangWatch if
- You want the LangWatch feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and LangWatch fits your workflow better
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 →
About LangWatch
LangWatch is an open source TypeScript platform for LLM evaluations and AI agent testing, licensed under Apache 2.0. It lives in the machine learning infrastructure ecosystem for teams that build LLM powered agents and need to test, simulate, evaluate, and monitor agents before release and in production.
read the full LangWatch overview →
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Frequently asked questions
Is llama_index or LangWatch more popular?
llama_index has 52,202 GitHub stars and LangWatch has 4,810. llama_index has the larger community by that measure.
Are llama_index and LangWatch free?
Both are open source. llama_index is licensed under MIT and LangWatch under Apache-2.0. Neither carries a licence fee.
What is the difference between llama_index and LangWatch?
llama_index is written in Python and LangWatch in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, llama_index or LangWatch?
Choose llama_index if you want the larger community (52,202 stars) or its MIT licence terms. Choose LangWatch if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.