LangChain
RAG & Memory · Free + paid
Framework for developing LLM-powered applications
At a glance
- Made by
- LangChain
- Korean
- None (English and a few others only)
- API
- Yes
- Available on
- API, CLI
- Open source
- MIT
- GitHub
- 147,812 stars · MIT
What is LangChain?
LangChain provides open-source agent frameworks (LangChain, LangGraph, Deep Agents) that work with any model provider. LangSmith is a platform for testing, deploying, monitoring, and improving agents, regardless of framework. It offers tracing, evaluation, deployment, sandboxes, an LLM gateway, a no-code agent builder (Fleet), and automatic problem diagnosis (Engine). It can be run in the cloud, in a hybrid setup, or self-hosted.
- Open-source agent frameworks (langchain, langgraph, deepagents)
- LangSmith observability (tracing) and evaluation
- Agent deployment (Agent Server, 30+ API endpoints)
- Isolated sandboxes for agent-generated code
- LLM Gateway (cost, fallbacks, PII removal)
- No-code agent builder Fleet
- Engine (automatic failure diagnosis and fix suggestions)
Who uses LangChain and for what
- Quickly build agents with the models developers prefer
- Trace, evaluate, and monitor the agents your team runs in production
Pricing
What you get for free — Yes (Developer: 1 seat, 5,000 base traces per month, then pay-as-you-go)
| Plan | Price | Main limits |
|---|---|---|
| Developer | $0/mo | 1 seat, 5k base traces per month, pay-as-you-go beyond that |
| Plus | $39/mo | Per seat, 10k base traces per month, 1 serverless deployment free, pay-as-you-go beyond that (LSU $1) |
| Enterprise | Contact sales | Custom pricing, self-hosted and hybrid |
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying. · Official pricing page
Combos that work well with LangChain
RAG-based comparison Q&A
ChatGPT (OpenAI) splits a question into search, tool call, and response generation steps. In LangChain, official document chunks and the pricing DB are connected to a search index. Answers without evidence are blocked and source links are returned.
Cost: Brain: API pay-as-you-go + subscription (ChatGPT) / Tool: open source + paid cloud-managed plan
RAG-based comparison Q&A
Claude splits a question into search, tool call, and response generation steps. In LangChain, official document chunks and the pricing DB are connected to the search index. Answers without evidence are blocked, and source links are returned.
Cost: Brain: freemium (free + paid subscription) + API pay-as-you-go / Tool: open source + paid cloud-managed plan
Comparison chatbot that cites sources
ChatGPT indexes official documents and the pricing DB as chunks with version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects search, tool calls, and answer generation, and Rerank orders the evidence. Questions with insufficient evidence are not answered by guessing and are directed to the official page link instead.
Cost: API pay-as-you-go + subscription (ChatGPT) / open source + paid managed cloud plan
Comparison chatbot that cites sources
Claude indexes official documentation and the pricing DB into chunks that carry a version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects search, tool calls, and answer generation, and Rerank orders the evidence. For questions with insufficient evidence, it does not guess an answer and instead points to the official page link.
Cost: Freemium (free + paid subscription) + API pay-as-you-go / open source + paid managed cloud plan
Comparison chatbot that cites sources
Gemini indexes official documentation and the pricing DB into chunks that carry a version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects search, tool calls, and answer generation, and Rerank orders the evidence. For questions with insufficient evidence, it does not guess an answer and instead points to the official page link.
Cost: Freemium (free + paid subscription) + API pay-as-you-go / open source + paid managed cloud plan
Comparison chatbot that cites sources
DeepSeek indexes official documents and the pricing DB into chunks with version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects retrieval, tool calls, and answer generation, and Rerank orders the evidence. For questions with insufficient evidence, it does not guess an answer and points to the official page link instead.
Cost: Open source (free) + API pay-as-you-go / open source + paid managed cloud plan
Comparison chatbot that cites sources
Perplexity indexes official documents and the pricing DB into chunks that carry a version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects search, tool calls, and answer generation, and Rerank orders the evidence. Questions with insufficient evidence are not answered by guesswork but directed to official page links.
Cost: Freemium (free + paid subscription) / open source + paid managed cloud plan
Comparison chatbot that cites sources
Grok-2 indexes official documents and the pricing DB into chunks that carry a version, URL, and collection time. In the LlamaIndex + LangChain + Cohere Rerank 3 combo, LangChain connects search, tool calls, and answer generation, and Rerank orders the evidence. Questions with insufficient evidence are not answered by guesswork but directed to official page links.
Cost: Subscription (including X subscription) + API pay-as-you-go / open source + paid managed cloud plan
AI tools similar to LangChain (alternatives)
LangChain vs. alternatives at a glance
| AI | Pricing | Combos on the map | Connected tools | Free | Cheapest monthly | Korean |
|---|---|---|---|---|---|---|
| LangChain | Free + paid | 18 | 5 | Yes | $39/mo | No |
| DSPy | Free + paid | 0 | 5 | — | — | No |
| Haystack | Free + paid | 0 | 5 | Yes | — | No |
| LlamaIndex | Free + paid | 18 | 5 | Yes | $50/mo | No |
| Semantic Kernel | Free + paid | 0 | 5 | — | — | Yes |
3 of these 5 tools have a free plan. Cheapest paid plan: LangChain ($39/mo).
Combo and connection counts are based on the relationships recorded on AI Galaxy Map (2026-10-26); they are not a quality ranking.
LangChain on AI Galaxy Map
- One of 21 AI tools in the RAG & Memory field.
- Connected to 5 other tools — #1 in its field.
- Part of 18 work combos recorded on the map.
Frequently asked questions
Can I use LangChain for free?
Yes (Developer: 1 seat, 5,000 base traces per month, then pay-as-you-go). Prices can change, so check the official site before paying.
What works well with LangChain?
Based on the combos on the map, there is a workflow such as "RAG-based comparison Q&A" that uses it together with GPT.
What AI can I use instead of LangChain?
Tools that do the same job, such as DSPy, Haystack, LlamaIndex, Semantic Kernel, are connected to it on the map.
Can I use LangChain in Korean?
None (English and a few others only)
Sources (official pages)
- https://docs.langchain.com/
- https://www.langchain.com/
- https://www.langchain.com/pricing
- https://github.com/langchain-ai/langchain
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying.