langchain
docs.langchain.com
The agent engineering platform.
Quick Information
- Category:
- Productivity
- Pricing:
- Freemium
- Platforms:
- Web
- Free Plan:
- Yes
- API Available:
- Yes
- Last Verified:
- September 2026
What Is langchain?
LangChain is an open-source framework for building LLM applications, remaining completely free (alongside its companion LangGraph framework) since the company monetizes through its separate observability platform, LangSmith, rather than the framework itself. LangSmith's Developer tier is free (5,000 traces/month, 14-day retention, one seat, basic evaluations), while Plus costs $39/seat/month (10,000 base traces, with overage at $2.50 per 1,000 traces beyond that).
A genuinely important cost-unpredictability detail worth understanding before budgeting for LangSmith specifically: usage is calculated in two separate units — LangChain Compute Units (LCU) at $1.50 and LangChain Storage Units (LSU) at $1.00 — with extended 400-day trace retention costing $5.00 per 1,000 traces, meaning two teams paying the same $39/seat license fee can end up with meaningfully different total bills depending on how much their agents actually run and how many traces they generate.
It's aimed at developers building LLM applications who want a free, open-source orchestration framework, with LangSmith's observability layer being the actual paid product — teams should model expected trace volume and compute/storage unit usage carefully before assuming the $39/seat license fee represents their full monthly cost. See our Developer Tools directory for related tools like LangSmith and Langfuse.
What Can You Use langchain For?
LLM application orchestration
Builds and orchestrates LLM-powered applications using an open-source framework.
Agent workflow development
Develops agentic workflows using LangChain alongside LangGraph.
LLM observability
Monitors and evaluates LLM application performance via the separate LangSmith platform.
langchain Features
- Open-source framework — Provides a free, open-source framework for building LLM applications.
- LangGraph — A companion framework for building agentic workflows, also free.
- LangSmith observability — Provides tracing, evaluation, and monitoring for LLM applications as a separate paid product.
Who Is langchain For?
- Developers — Builds LLM applications using a free, open-source orchestration framework.
- Teams monitoring LLM apps — Uses LangSmith’s paid observability tier to trace and evaluate agent behavior in production.
langchain Pros & Limitations
What We Like
- The core framework (and LangGraph) remains genuinely free and open-source
- LangSmith’s Developer tier (5,000 free traces/month) allows meaningful evaluation before paying
- Established, widely-adopted framework with a large ecosystem of integrations
Limitations
- LangSmith costs are unpredictable — usage-based compute and storage units mean bills vary significantly by workload
- Two teams on the same $39/seat plan can end up with meaningfully different total costs
- Extended trace retention (400 days) adds further cost on top of the base license fee
langchain Pricing
| Plan | Price | Main Features |
|---|---|---|
| Framework (open source) | Free | LangChain + LangGraph |
| LangSmith Developer | Free | 5,000 traces/month, 14-day retention, 1 seat |
| LangSmith Plus | $39/seat/month | 10,000 base traces, $2.50/1,000 traces overage |
Pricing was last verified September 2026. Check the official website for the latest pricing.
AI Listing Jungle Ranking
- Global Rank:
- #73
- Overall Score:
- 78.8/100
- Monthly Users:
- –
- Rank Change:
- ▲ 13
This ranking reflects AI Listing Jungle's own independent scoring methodology and is not an endorsement by langchain or its company. How Our Rankings Work
Frequently Asked Questions
Is LangChain free?
Yes, the open-source framework (and LangGraph) is completely free.
What does LangChain monetize?
The separate LangSmith observability platform, not the core framework itself.
How much does LangSmith cost?
Free for the Developer tier (5,000 traces/month), then $39/seat/month for Plus with usage-based overage.
Why do LangSmith costs vary between teams?
Usage is billed via Compute and Storage Units that scale with actual agent activity, not just the flat seat fee.
Our Take
LangChain's core framework remaining genuinely free while monetizing through LangSmith observability is a sensible model, but LangSmith's usage-based billing makes real cost hard to predict upfront.
Model expected trace volume and compute/storage unit usage carefully before assuming the $39/seat fee is the full monthly cost.
langchain Alternatives
langchain Comparisons
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