# langchain vs pydantic-ai
_Agent Frameworks · independent comparison_

> langchain and pydantic-ai are both open-source agent frameworks you can self-host for free. langchain has wider GitHub adoption — 144k stars vs 19k. Neither is universally better — pick by fit.

## Side by side

**langchain**
- Open source · Framework · 144k★ · Python · MIT · active 3 days ago
- Best for: Builders who want composable primitives and the broadest ecosystem of integrations for LLM applications.
- Avoid if: You want a ready-made autonomous agent out of the box — this is a framework, not an agent.
- [listing](https://agentsearchengine.app/agents/langchain) · [official](https://docs.langchain.com/langchain/)

**pydantic-ai**
- Open source · Framework · 19k★ · Python · MIT · active 2 days ago
- Best for: Python teams that want type-safe agent development with the Pydantic philosophy.
- Avoid if: You are not working in Python.
- [listing](https://agentsearchengine.app/agents/pydantic-ai) · [official](https://pydantic.dev/pydantic-ai)

## Key differences

- langchain has wider GitHub adoption — 144k stars vs 19k.

## Which to choose

**Choose langchain if:** Builders who want composable primitives and the broadest ecosystem of integrations for LLM applications.

**Choose pydantic-ai if:** Python teams that want type-safe agent development with the Pydantic philosophy.

## FAQ

**What's the main difference between langchain and pydantic-ai?**
langchain has wider GitHub adoption — 144k stars vs 19k.

**Is langchain or pydantic-ai better?**
Neither is universally better. langchain is the stronger fit for Builders who want composable primitives and the broadest ecosystem of integrations for LLM applications; pydantic-ai for Python teams that want type-safe agent development with the Pydantic philosophy. Use the side-by-side specs to decide by your own constraints.

**Is langchain or pydantic-ai free?**
langchain is free to run and self-host; pydantic-ai is free to run and self-host. Both are free to self-host — you only pay for the infrastructure and any model or API usage.

**Which is more popular, langchain or pydantic-ai?**
By GitHub stars — a proxy for open-source adoption — langchain is ahead (144k vs 19k). Stars measure attention, not necessarily the better fit for you.

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Source: [Agent Search Engine](https://agentsearchengine.app) — https://agentsearchengine.app/compare/langchain-vs-pydantic-ai