LangChain's platform for tracing, evaluating and monitoring LLM apps and agents, usable with or without LangChain; also hosts agent deployments.
Pricing and hosting
- Pricing
- Free plan
- Free plan
- 5k base traces/mo, 1 seat
- Open source
- No
- Self-hosted
- Yes
- Launched
- 2023
- Status
- Active
- Website
- langchain.com
Plans and prices change; check the tool's own site before you decide.
What it does
LLM and AI observability checklist
10 of 10 confirmed in LangSmith's own documentation. The same checklist is used for every tool in LLM observability.
- LLM call tracing Yes
- Agent and multi-step traces Yes
- Token and cost tracking Yes
- Prompt management Yes
- Evaluations Yes
- Datasets and experiments Yes
- User feedback Yes
- OpenTelemetry support Yes
- Playground Yes
- Alerts Yes
Checked against: docs.langchain.com, docs.langchain.com (2), docs.langchain.com (3), docs.langchain.com (4), docs.langchain.com (5), docs.langchain.com (6)
Alternatives to LangSmith
Other llm and ai observability tools. See all 22.
-
AgentOps Observability for AI agents: records agent sessions with LLM calls, tool use and costs so you can replay and debug runs; SDK and app are open source. -
Arize AX Arize's hosted AI observability and evaluation platform for agents and ML models: tracing, online evals, monitors and dashboards. -
Arize Phoenix Source-available LLM tracing and evaluation tool built on OpenTelemetry and OpenInference; run it locally, in a notebook or on your servers to inspect traces and score outputs. -
Braintrust Evaluation and observability platform for AI products: logs production traces, runs evals and scorers, and offers a prompt playground and datasets. -
Confident AI Evaluation and observability platform from the makers of the open source DeepEval library: LLM tracing, regression tests in CI, and red teaming. -
Future AGI Open source platform to trace, evaluate, simulate and guard LLM and agent apps, including an AI gateway. -
Galileo AI evaluation and observability platform with tracing, evaluation metrics and real-time guardrails for agents; hosted, VPC or on-prem. -
Helicone Open source LLM proxy and logging: point your provider base URL at it to record every request with cost, latency and user, plus caching and rate limits. -
HoneyHive Observability and evaluation platform for AI agents: OpenTelemetry-based tracing, automated and human evals, prompt versioning and production monitoring. -
Laminar Open source observability for AI agents: OpenTelemetry-based tracing, evaluations and analysis of agent runs, self-hostable or cloud. -
Langfuse Open source LLM engineering platform: traces LLM and agent calls, manages prompts, runs evaluations and tracks cost and latency. Self-host or use the cloud; acquired by ClickHouse in 2026. -
LangWatch Open source LLMOps platform: traces LLM and agent runs, runs evaluations and agent simulations, and helps optimize prompts; cloud or self-managed.