What are the best Arize Phoenix alternatives in 2026?
The best open-source Arize Phoenix alternatives in 2026 are LangFuse, Promptfoo, DeepEval, Ragas, LM Evaluation Harness. These tools cover the same use cases as Arize Phoenix — ai observability platform for llm tracing and evaluation — with the advantage of being open-source, free to self-host, and backed by active communities. Top picks are ranked by GitHub stars and community adoption, so you can find a drop-in replacement that fits your workflow.
Open-source LLM engineering platform for observability
Test and evaluate LLM outputs and prompt quality
Unit testing framework for LLM outputs and RAG pipelines
Evaluation framework for RAG pipelines
Framework for evaluating language models on NLP tasks
ML and LLM monitoring and evaluation platform
State-of-the-art ML models for NLP, vision and audio
Framework for building LLM-powered applications
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Last updated: Aug 28, 2026 · Curated by AI Tools Hub Editorial · About · Contact · Privacy