Langfuse
8.2#1 in prompting toolFrom $29 a monthFree planWebAPILinuxSelf-hosted
VisitLangfuse vs LangSmith
What both publish
| Fact | Langfuse | LangSmith |
|---|---|---|
| Documentation | Documentation covers observability, prompt management, evaluation, metrics, APIs, SDKs, integrations, compatibility, deployment, and security with versioned self-hosting guides. | LangChain publishes reference documentation, integration guides, deployment instructions, a CLI guide and a REST API reference. |
| Evaluation | Evaluation features include LLM-as-a-judge, code evaluators, user feedback, manual labeling, datasets, and experiments. | Evaluation supports offline datasets, online production evaluations, human annotation queues and side-by-side experiment comparison. |
| Funding | Crunchbase lists one seed funding round with five investors, including Y Combinator, La Famiglia, and Lightspeed Venture Partners, but hides the total amount. | LangChain announced a $125 million Series B at a $1.25 billion valuation on October 20, 2025. |
| Headquarters | Berlin, Germany; San Francisco, United States | San Francisco, California, United States |
| Integrations | Langfuse lists more than 100 integrations spanning OpenTelemetry, Python and TypeScript, model providers, agent frameworks, gateways, and developer tools. | Documented integrations cover OpenAI, Anthropic, Bedrock, Gemini, Mistral, LiteLLM, OpenTelemetry, CrewAI, Vercel AI SDK, PydanticAI, AutoGen and many other frameworks and providers. |
| Observability | Hierarchical traces capture LLM calls, tool invocations, and retrieval steps, with filtering by user, session, cost, latency, and metadata. | Its observability features include agent tracing, cost tracking, online LLM-as-judge and code evaluations, trajectory monitoring, and webhook or PagerDuty alerts. |
| Rating on G2 | 4.5 out of 5 from 1 review | 4.4 out of 5 from 78 reviews. |
| Rating on Gartner Peer Insights | 4.6 out of 5 from 5 ratings | 4.4 out of 5 from 25 ratings. |
| SDKs | Official SDKs are Python v5 and JavaScript/TypeScript v6; other languages can use OpenTelemetry instrumentation. | Official SDK documentation is provided for Python, JavaScript/TypeScript, Go and Java. |
Langfuse plans
- HobbyFree
- Core$29 a month
- Pro$199 a month
- Teams Add-on$300 a month
- Enterprise$2,499 a month
LangSmith plans
- DeveloperFree
- Plus$39 a month
- EnterprisePriced on request
Pick Langfuse if…
Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools. It also supports teams that want to self-host the core on their own infrastructure.
Pick LangSmith if…
LangSmith suits teams building or operating AI agents that need evaluation, prompt workflows, and observability. It supports both hosted and self-hosted deployment options.