Compare frameworks
LlamaIndex vs Pydantic AI vs LangChain
Every figure below carries the source that reported it and the moment it was observed. Values that failed validation are withheld rather than shown, and a dash means no source we track carries that field for that framework.
| Field | LlamaIndex | Pydantic AI | LangChain |
|---|---|---|---|
| Stars | 52,334Synced from sourceCurrent3h ago | 20,220Synced from sourceCurrent3h ago | 147,178 (highest of the compared values)Synced from sourceCurrent3h ago |
| downloads | 149,503Synced from sourceCurrent3h ago | 3,076,771Synced from sourceStale1mo ago· past SLA | 3,201,198 (highest of the compared values)Synced from sourceCurrent3h ago |
| Last commit | 2026-09-27Synced from sourceCurrent3h ago | 2026-09-28Synced from sourceCurrent3h ago | 2026-09-27Synced from sourceCurrent3h ago |
| Language | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago | pythonSeeded, unreviewedwritten 1mo ago |
| Licence | MITSynced from sourceCurrent3h ago | MITSynced from sourceCurrent3h ago | MITSynced from sourceCurrent3h ago |
| Archived | noSynced from sourceCurrent3h ago | noSynced from sourceCurrent3h ago | noSynced from sourceCurrent3h ago |
| Category | ragSeeded, unreviewedwritten 1mo ago | structured-outputSeeded, unreviewedwritten 1mo ago | orchestrationSeeded, unreviewedwritten 1mo ago |
| Contributors | 2001Synced from sourceCurrent3h ago | 609Synced from sourceCurrent3h ago | 3741Synced from sourceCurrent3h ago |
| Forks | 8232Synced from sourceCurrent3h ago | 2796Synced from sourceCurrent3h ago | 24634Synced from sourceCurrent3h ago |
| Maintainer | LlamaIndexSeeded, unreviewedwritten 1mo ago | PydanticSeeded, unreviewedwritten 1mo ago | LangChainSeeded, unreviewedwritten 1mo ago |
| npm downloads, monthly | 445795Synced from sourceCurrent3h ago | — | 10682493Synced from sourceCurrent3h ago |
| npm downloads, weekly | 149503Synced from sourceCurrent3h ago | — | 3201198Synced from sourceCurrent3h ago |
| npm package | llamaindexSynced from sourceCurrent3h ago | — | langchainSynced from sourceCurrent3h ago |
| npm window ends | 2026-09-26Synced from sourceCurrent3h ago | — | 2026-09-26Synced from sourceCurrent3h ago |
| Open issues | 896Synced from sourceCurrent3h ago | 1013Synced from sourceCurrent3h ago | 569Synced from sourceCurrent3h ago |
| PyPI downloads, monthly | — | 13478631Synced from sourceStale1mo ago· past SLA | — |
| PyPI downloads, weekly | — | 3076771Synced from sourceStale1mo ago· past SLA | — |
| PyPI package | llama-indexSynced from sourceCurrent3h ago | pydantic-aiSynced from sourceCurrent3h ago | langchainSynced from sourceCurrent3h ago |
| PyPI released | 2026-09-21T16:22:20.056831ZSynced from sourceCurrent3h ago | 2026-09-25T23:32:17.554286ZSynced from sourceCurrent3h ago | 2026-09-18T17:31:10.056247ZSynced from sourceCurrent3h ago |
| Requires Python | <4.0,>=3.10Synced from sourceCurrent3h ago | >=3.10Synced from sourceCurrent3h ago | <4.0.0,>=3.10.0Synced from sourceCurrent3h ago |
| PyPI version | 0.14.25Synced from sourceCurrent3h ago | 2.51.0Synced from sourceCurrent3h ago | 1.4.2Synced from sourceCurrent3h ago |
| Repository | https://github.com/run-llama/llama_indexSynced from sourceCurrent3h ago | https://github.com/pydantic/pydantic-aiSynced from sourceCurrent3h ago | https://github.com/langchain-ai/langchainSynced from sourceCurrent3h ago |
Sources: GitHub REST API, npm registry downloads, PyPI registry metadata, pypistats.org downloads. Most recent observation 3h ago. Where a row is marked, ▲ is the highest of the values shown and ▼ the lowest — arithmetic on the figures above, not a ranking or a recommendation. Rows where neither extreme is meaningful are left unmarked rather than given a direction they do not have.
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