9 Best Open Source LangSmith Alternatives
A curated collection of the 9 best open source and self-hosted alternatives to LangSmith in 2026.
Looking for a free, privacy-friendly, or self-hosted replacement for LangSmith in 2026? The top open-source alternative is Langfuse — Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications..
Other highly rated open-source LangSmith alternatives include Arize Phoenix, OpenLLMetry and Helicone.
Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications.
Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications.
Open-source platform for LLM tracing, evaluation, and optimization. Features automatic instrumentation, prompt playground, and real-time AI application monitoring.
Open-source platform for LLM tracing, evaluation, and optimization. Features automatic instrumentation, prompt playground, and real-time AI application monitoring.
Open-source observability platform for LLMs using OpenTelemetry. Monitor performance, track costs, and debug AI applications with just 2 lines of code.
Open-source observability platform for LLMs using OpenTelemetry. Monitor performance, track costs, and debug AI applications with just 2 lines of code.
Open-source platform for logging, monitoring, and debugging LLM applications. Route, debug, and analyze AI apps with comprehensive observability tools.
Open-source platform for logging, monitoring, and debugging LLM applications. Route, debug, and analyze AI apps with comprehensive observability tools.
Open-source platform for monitoring AI agents: captures traces, surfaces failure patterns, alerts on issues, and helps you verify fixes with automated evals.
Open-source platform for monitoring AI agents: captures traces, surfaces failure patterns, alerts on issues, and helps you verify fixes with automated evals.
Open-source LLMOps platform providing prompt management, evaluation, and observability tools for building robust AI applications with team collaboration.
Open-source LLMOps platform providing prompt management, evaluation, and observability tools for building robust AI applications with team collaboration.
Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence.
Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence.
Open-source observability platform for GenAI and LLM applications. Real-time monitoring, distributed tracing, prompt management, and AI model evaluation built on OpenTelemetry.
Open-source observability platform for GenAI and LLM applications. Real-time monitoring, distributed tracing, prompt management, and AI model evaluation built on OpenTelemetry.
Drop-in observability platform for OpenAI, Anthropic, and Gemini that logs every request, tracks costs, traces agent workflows, and flags anomalies and PII.
Drop-in observability platform for OpenAI, Anthropic, and Gemini that logs every request, tracks costs, traces agent workflows, and flags anomalies and PII.
About LangSmith
Debug, test, and monitor LLM applications with comprehensive tracing, evaluation datasets, and performance analytics for production-ready AI systems.