LangSmith vs LangWatch
LangSmith
langchain.com
LangWatch
langwatch.aiSide by side
| Figure | LangSmith | LangWatch |
|---|---|---|
| Price from | $39/mo | €29/mo |
| Free plan | Yes | Yes |
| Free trial | — | Yes |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 3 |
| Spec score · AI Agent Observability Tools | 9.1 (#4) | 9.1 (#5) |
| Spec score · AI LLM Observability Tools | 9.1 (#3) | 9.1 (#4) |
| Spec score · AI Agent Evaluation Tools | 9.1 (#4) | 9.0 (#5) |
| Spec score · AI LLM Evaluation Tools | 9.1 (#5) | 9.1 (#6) |
| Spec score · Model Monitoring Software | 9.0 (#4) | 9.0 (#5) |
| Spec score · LLM Observability Tools | 9.0 (#5) | 9.0 (#6) |
| Spec score · Llm Monitoring | 8.9 (#6) | 8.9 (#7) |
| Deployment | Deployment provides managed or self-hosted agent servers with streaming, cron scheduling, authentication, MCP support and more than 30 API endpoints. | LangWatch offers managed cloud, self-hosted, and hybrid deployment; its pricing page says self-hosting uses Docker Compose and the customer's ClickHouse. |
| Documentation | LangChain publishes reference documentation, integration guides, deployment instructions, a CLI guide and a REST API reference. | Documentation covers introduction, integrations, CLI, MCP, agent testing, observability, evaluations, datasets, prompt management, self-hosting and API reference. |
| Funding | LangChain announced a $125 million Series B at a $1.25 billion valuation on October 20, 2025. | Crunchbase lists LangWatch as a private pre-seed company with two funding rounds and investors including Volta Ventures and Antler. |
| Headquarters | San Francisco, California, United States | Amsterdam |
| Integrations | Documented integrations cover OpenAI, Anthropic, Bedrock, Gemini, Mistral, LiteLLM, OpenTelemetry, CrewAI, Vercel AI SDK, PydanticAI, AutoGen and many other frameworks and providers. | Official integrations cover OpenAI, Anthropic, Google Gemini, Bedrock, Azure OpenAI, Vertex AI, Groq, Ollama and LiteLLM. |
| Observability | Its observability features include agent tracing, cost tracking, online LLM-as-judge and code evaluations, trajectory monitoring, and webhook or PagerDuty alerts. | Tracing captures nested agent spans, sessions, users, token usage, cost, topics and multimodal payloads. |
| Rating on G2 | 4.4 out of 5 from 78 reviews. | 0.0 out of 5 from 0 reviews |
| Rating on Product Hunt | 4.8 out of 5 from 19 reviews. | 5.0 out of 5 from 5 reviews |
| Security | LangSmith's trust center lists SOC 2 Type II, ISO 27001:2022, GDPR and HIPAA compliance. | The trust center states AES-256 encryption at rest, TLS 1.2+ in transit, AWS KMS, RBAC, MFA, SSO, encrypted backups and GDPR controls. |
| Self-hosting | Enterprise customers can run LangSmith self-hosted or hybrid on Kubernetes in AWS, Google Cloud or Azure. | Self-hosting is available with a Node.js command for local use and Docker, Kubernetes/Helm or VPC deployment options. |
| Support | The Developer plan includes community support, and the Enterprise plan lists a support SLA. | Developer users receive GitHub and Discord community support, while Growth includes private Slack or Teams support. |
| System requirements | Agent Server deployments require PostgreSQL and Redis; self-hosted installations may use customer-managed PostgreSQL and Redis. | The self-host command requires Node.js 24 or newer on macOS or glibc-based Linux. |
| What it does | LangSmith is LangChain's framework-agnostic platform for observing, evaluating and deploying AI agents. | LangWatch is an AI-agent engineering platform for testing, evaluating, observing, governing and improving agents across development and production. |
Plans
In their own words
LangSmith
LangSmith is a commercial agent-engineering platform for building, evaluating, deploying, monitoring, and improving AI agents. It supports offline evaluations on curated datasets and real-time scoring of production interactions. Evaluation methods include human review, heuristic checks, LLM-as-judge evaluators, pairwise comparisons, and custom Python or TypeScript evaluators. Annotation queues route runs to subject-matter experts for feedback that can calibrate evaluations, improve prompts, or augment datasets. The Playground compares prompt versions or model providers, and LangSmith chat can auto-improve prompts. Observability includes agent and retrieval tracing, token and general cost tracking, trajectory monitoring, online evaluations, and webhook or PagerDuty alerts. Traces can arrive through SDKs or an API from LangGraph, custom Python, or other stacks; SDKs are listed for Python, TypeScript, Go, and Java. Hosting ranges from cloud to hybrid and self-hosted Enterprise options. The Developer plan costs nothing, Plus costs $39 a month, and Enterprise pricing is custom.
LangWatch
LangWatch is an AI agent engineering platform for teams preparing agents for production. Simulations cover multi-turn conversations, tool use, recovery, and business outcomes before launch. Evaluations can run on datasets, production traffic, or in CI/CD workflows that gate merges. Traces show agent steps alongside cost, tokens, duration, errors, evaluations, and annotations. Integrations include Python and TypeScript SDKs, OpenTelemetry, REST ingestion, model providers, and frameworks such as LangGraph, LangChain, CrewAI, and DSPy. Voice-agent testing supports OpenAI Realtime, Gemini, ElevenLabs, Google Live API, Pipecat, WebSocket bots, and Twilio. Deployment options are managed cloud, self-hosted, and hybrid; self-hosting uses Docker Compose and the customer’s ClickHouse. LangWatch is open source under Apache 2.0. The Developer plan costs nothing and includes 50k events per month, 14-day data access, and two users. Growth costs €29 a month per core seat and includes 200k events. The trust center lists encryption, access controls, privacy features, and enterprise DPAs.