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LangChain

Framework for LLM applications

The most widely-used framework for building LLM-powered applications, available in Python and JavaScript. Provides abstractions for chains, agents, RAG, memory, tool usage, and structured output. Integrates with 100+ LLM providers, vector stores, document loaders, and tools. LangSmith offers tracing and evaluation. LangGraph enables stateful, multi-agent workflows with cycles. 100K+ GitHub stars. The de facto standard for LLM application development despite growing alternatives like LlamaIndex.

About LangChain

LangChain is an open-source framework for building applications powered by large language models, providing composable primitives for prompts, models, memory, tools, retrievers, and higher-level patterns like chains, agents, and graphs. It solves the challenge of connecting LLMs to external data sources, APIs, and tools while managing complex multi-step workflows that go beyond simple prompt-response interactions. LangChain enables developers to build production-grade AI applications including chatbots, RAG pipelines, autonomous agents, and multi-agent systems through a modular architecture that supports rapid iteration and experimentation.

LangChain differentiates itself with over 1,000 integrations spanning vector databases, model providers, document loaders, and tool ecosystems, ensuring developers face no vendor lock-in. Its multi-agent orchestration engine coordinates how agents interact, sequence tasks, share context, and respond to failures within a structured yet flexible framework. LangGraph extends LangChain with stateful, multi-step agent workflows using a graph-based execution model, while LangSmith provides observability, evaluation, and deployment tools for monitoring agent performance in production environments.

LangChain is designed for AI engineers and development teams building intelligent assistants, autonomous agents, RAG systems, and AI-integrated enterprise tools across Python and JavaScript ecosystems. It integrates seamlessly with OpenAI, Anthropic, Google, Hugging Face, and dozens of other model providers, alongside vector stores like Pinecone, Weaviate, and Chroma. The framework has become a cornerstone of the AI application development ecosystem, with an active open-source community and enterprise-grade tooling through LangSmith and LangServe for deployment and monitoring.

Pricing & Platform Specs

Pricing Summary

Freemium open-source LLM application development framework (MIT License, 100k+ GitHub stars). The core Python and TypeScript libraries (pip install langchain, @langchain/core) are 100% free ($0) with no software licensing fees. LangSmith observability offers a Developer plan ($0/mo for 1 seat with 5k traces/mo), a Plus plan at $39/seat/month with 50k traces/mo, prompt engineering playground, and automated LLM evaluations, and an Enterprise tier with custom pricing for dedicated VPC/BYOC deployments, SAML SSO, RBAC, and dedicated 99.9% SLAs.

full pricing breakdown →

Supported Platforms

Python, Node.js

Explore categories, tags & use cases

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Open Source

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Side-by-Side Comparisons

LangChain logo
LangChain
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CrewAI logo
CrewAI
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LangGraph logo
LangGraph

LangChain vs CrewAI vs LangGraph — Framework Breadth vs Agent Teams vs Stateful Orchestration

LangChain, CrewAI, and LangGraph are three of the most common starting points for agent-framework decisions. LangChain gives the broad application framework, CrewAI gives an approachable role-based crew model, and LangGraph gives explicit stateful orchestration for production agents. If the goal is reliable multi-step agent systems rather than quick demos, LangGraph is the strongest overall winner.

LangChain logo
LangChain
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Pydantic AI logo
Pydantic AI
vs
CrewAI logo
CrewAI

LangChain vs Pydantic AI vs CrewAI — Broad Framework vs Typed Agents vs Role-Based Crews

LangChain, Pydantic AI, and CrewAI answer different versions of the same question: how should teams build practical AI agents in 2026? LangChain remains the broadest ecosystem, Pydantic AI gives Python teams a typed and schema-first way to build reliable agents, and CrewAI makes role-based multi-agent workflows approachable. For teams specifically looking for a cleaner LangChain alternative, Pydantic AI is the sharpest winner; LangChain still wins on breadth, while CrewAI wins for quick crew-style prototypes.

View 13 more comparisons

Community experience

Sources & verification

Sources checked
Content verified

Verification dates are editorial checks. Routine CMS saves and automatic updatedAt timestamps do not advance them.

FAQ

What is LangChain?

The most widely-used framework for building LLM-powered applications, available in Python and JavaScript. Provides abstractions for chains, agents, RAG, memory, tool usage, and structured output. Integrates with 100+ LLM providers, vector stores, document loaders, and tools. LangSmith offers tracing and evaluation. LangGraph enables stateful, multi-agent workflows with cycles. 100K+ GitHub stars. The de facto standard for LLM application development despite growing alternatives like LlamaIndex.

Is LangChain free?

LangChain offers a free tier alongside paid plans. Freemium open-source LLM application development framework (MIT License, 100k+ GitHub stars). The core Python and TypeScript libraries (pip install langchain, @langchain/core) are 100% free ($0) with no software licensing fees. LangSmith observability offers a Developer plan ($0/mo for 1 seat with 5k traces/mo), a Plus plan at $39/seat/month with 50k traces/mo, prompt engineering playground, and automated LLM evaluations, and an Enterprise tier with custom pricing for dedicated VPC/BYOC deployments, SAML SSO, RBAC, and dedicated 99.9% SLAs.

Is LangChain open source?

Yes — LangChain is open source.

Is LangChain still maintained?

Yes — LangChain is active. Its listing was last verified on September 6, 2026.

What are the best LangChain alternatives?

The first editor-selected LangChain alternatives are RAG-Anything, Anchor Browser, PageIndex.

How does LangChain score in our review?

The published editorial review lists LangChain at 82/100 overall across speed, privacy, and developer experience. Check the review's evidence status and test metadata for its verification level.