LangChain vs Pydantic AI

as AI assistants see them, week of 2026-09-14

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LangChain clearly leads here, scoring 44 overall versus Pydantic AI's 15, and showing up in 44 of 71 answers compared to just 19 for Pydantic AI. Ask about building AI agents in general, or picking an agent framework, and LangChain gets named in every single answer. Pydantic AI does hold its own on developer-focused and open-source framework questions, matching LangChain 3-for-3 there, with Claude notably keener on it (41) than ChatGPT, Perplexity or Gemini, which never mentions it at all. Head-to-head, LangChain comes out ahead on 14 questions, Pydantic AI on none, with 6 ties. Neither gets named for voice agents or non-technical founders.

Head to head

metric	LangChain	Pydantic AI
score	44	15
questions won	18	15

By assistant

LangChain

assistant	score	named in, this week	usual spot, this week
ChatGPT	47	55% of answers	#2.1
Claude	49	80% of answers	#5.2
Gemini	56	83% of answers	#4.3
Perplexity	33	37% of answers	#1.7

Pydantic AI

assistant	score	named in, this week	usual spot, this week
ChatGPT	6	10% of answers	#5.5
Claude	41	75% of answers	#6.6
Gemini	0	0% of answers
Perplexity	7	11% of answers	#5.0

Where they differ

Only LangChain gets named for

What's the best way to give an AI agent memory across sessions?
What's the best no-code tool to build an AI agent?
What's the best tool to monitor and debug AI agents in production?

Only Pydantic AI gets named for

nothing exclusive

More comparisons

Not sold on either?

Scores count how often each assistant names a product, weighted by position. How the score works · Full AI agent builders leaderboard