langchain vs pydantic-ai
langchain and pydantic-ai are both agent frameworks. langchain is The agent engineering platform, while pydantic-ai is aI Agent Framework, the Pydantic way. Here's an independent, side-by-side look at how they compare — and which fits.
langchain and pydantic-ai are both open-source agent frameworks you can self-host for free. langchain has wider GitHub adoption — 141k stars vs 18k. Neither is universally better — pick by fit.
Side by side
| Spec | langchain | pydantic-ai |
|---|---|---|
| Type | Framework | Framework |
| Model | Open source | Open source |
| Pricing | Open source | Open source |
| GitHub stars | 141,411 | 18,299 |
| Language | Python | Python |
| License | MIT | MIT |
| Last activity | Jul 2026 | Jul 2026 |
Key differences
- langchain has wider GitHub adoption — 141k stars vs 18k.
Builders who want composable primitives and the broadest ecosystem of integrations for LLM applications..
Python teams that want type-safe agent development with the Pydantic philosophy..
Frequently asked
- What's the main difference between langchain and pydantic-ai?
- langchain has wider GitHub adoption — 141k stars vs 18k.
- 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 (141k vs 18k). Stars measure attention, not necessarily the better fit for you.
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