6 Best Open Source Weights and Biases Alternatives
A curated collection of the 6 best open source and self-hosted alternatives to Weights and Biases in 2026.
Looking for a free, privacy-friendly, or self-hosted replacement for Weights and Biases 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 Weights and Biases alternatives include Arize Phoenix, Latitude and LangWatch.
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 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.
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.
Open source ML experiment tracking platform with parameter and gradient logging, media tracking, real-time alerts, and full Weights & Biases API compatibility.
Open source ML experiment tracking platform with parameter and gradient logging, media tracking, real-time alerts, and full Weights & Biases API compatibility.
About Weights and Biases
The leading AI developer platform to train and fine-tune models, manage models from experimentation to production, and track and evaluate GenAI applications powered by LLMs.