Developer
Free
- Up to 5,000 base traces/mo, then pay-as-you-go
- 14-day base retention
- One seat
- Basic evaluations
LangSmith: Pricing, Features, Pros & Cons
Founded 2023|San Francisco, CA|51-200 people|Freemium
What is LangSmith?
LangSmith is LangChain's commercial platform for building and running AI agents. It covers observability, evaluation, prompt management, and deployment, and its tracing works natively with LangChain and LangGraph and with other frameworks through SDKs for Python, TypeScript, Go, and Java plus OpenTelemetry. Teams already on LangChain get trace structure for every chain, tool, and agent step without adding instrumentation.
Pricing combines seats and traces. The free Developer plan is limited to one seat, and each Plus seat costs $39 a month, so the bill grows with team size as well as traffic. Base traces are kept for 14 days, and keeping a trace longer moves it to a pricier extended tier. Self-hosting and hybrid deployment are only available on Enterprise.
LangSmith also added an LLM Gateway, currently in beta, for multi-provider access, fallbacks, and spend limits. If per-seat pricing or a gateway still in beta is a sticking point, the LangSmith alternatives worth comparing include platforms that ship a production gateway alongside tracing and evals.
Key features
Core capabilities this platform advertises.
- Native tracing for LangChain and LangGraph
- OpenTelemetry and multi-language SDKs
- Offline and online evaluations
- Annotation queues and datasets
- Prompt Hub with versioning
Strengths and tradeoffs
What this tool does well, and the limitations to keep in mind.
Pros
- Native LangChain and LangGraph tracing with no extra instrumentation
- Evals, datasets, and annotation queues sit in the same workspace as traces
- Tracing, deployment, and sandboxes from one vendor
- Framework-agnostic SDKs and OpenTelemetry support
Cons
- Per-seat pricing on Plus, and the free plan allows one seat
Plans & pricing
What's included in each plan, and how the tiers compare.
Plus
$39
Per seat/month
Common use cases
Teams building agents on LangChain or LangGraph who want tracing, evals, and deployment from one vendor
- Debugging LangChain and LangGraph agents
- Evaluating agent output against datasets
- Human review through annotation queues
- Deploying long-running agents
Using LangSmith with Respan
Teams building on LangChain or LangGraph can trace with Respan through respan-instrumentation-langchain, which captures every chain, model, tool, retriever, and agent run. Point model calls at the Respan gateway too, and each request is routed across 1,000+ models, traced, and scored on the same record.
- Trace LangChain and LangGraph runs with one instrumentor
- Route model calls across 1,000+ models through one OpenAI-compatible endpoint
- Score output on live production traffic with automated evals
- Unlimited seats on the free plan, with no per-seat pricing
Trace, route, and score your LangChain agents
10KFree traces/mo
1,000+Models
Best LangSmith alternatives & competitors
Top companies in Observability, Prompts & Evals you can use instead of LangSmith.
Compare LangSmith
Side-by-side comparisons with other tools in this category.
Best integrations for LangSmith
Companies from adjacent layers in the AI stack that work well with LangSmith.
Last verified: March 9, 2026
