Langfuse vs LangSmith

Two observability platforms for LLM applications

Comparison of features and use cases for Langfuse and LangSmith in production LLM monitoring.

The contenders

Each pick links through to its full Directories entry.

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not yet in the index

Teams wanting open-source transparency with hosted options

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not yet in the index

LangChain users needing deep integration with the ecosystem

Same criteria, three answers. The verdict is opinionated and lives below the table.

Criterion	langfuse	langsmith
Open Source	Yes (with hosted option)	No (proprietary SaaS)
Pricing Model	Usage-based with free tier	Credit-based with minimum spend
LangChain Integration	Basic support	Native deep integration
Custom Metrics	Full customization	Limited predefined metrics
Trace Visualization	Interactive tree views	Linear execution timeline
Alerting	Webhook-based alerts	In-app notification system

Langfuse wins for open-source flexibility

LangSmith wins for LangChain-native workflows

Choose based on your need for transparency vs tight ecosystem integration

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