LangSmith vs OpenRouter
LangSmith
langchain.com
OpenRouter
openrouter.aiSide by side
| Figure | LangSmith | OpenRouter |
|---|---|---|
| Price from | $39/mo | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 3 | 4 |
| Spec score · LLM Gateway Software | 9.2 (#1) | 7.7 (#17) |
| Spec score · LLM gateways | 9.3 (#2) | 7.8 (#20) |
| Spec score · Llm Developer Tools | 9.0 (#3) | 7.5 (#18) |
| Founded | 2023 | 2023 |
| Integrations | Documented integrations cover OpenAI, Anthropic, Bedrock, Gemini, Mistral, LiteLLM, OpenTelemetry, CrewAI, Vercel AI SDK, PydanticAI, AutoGen and many other frameworks and providers. | The integrations directory lists tools including Open WebUI, Cline, LangChain, Vercel AI SDK, and Zapier as compatible with OpenRouter. |
| SDKs | Official SDK documentation is provided for Python, JavaScript/TypeScript, Go and Java. | The quickstart lists OpenRouter client SDK installation options for TypeScript and Python. |
| Support | The Developer plan includes community support, and the Enterprise plan lists a support SLA. | OpenRouter directs users to its help center, support ticket form, documentation, and community Discord; pricing lists community, email, or dedicated support according to plan. |
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.
OpenRouter
OpenRouter has no write-up on Specifiction yet; its figures are above.