The best Langfuse alternatives
8 tools that do a similar job to Langfuse, 3 of them open source. Each entry says what it does and who it suits, so you can pick the one that fits instead of the most famous.
You're replacing
LangfuseAn open-source LLM engineering platform for tracing, prompt management, evaluations and cost tracking.
- 1
Arize Phoenix
AI tool · Open source
An open-source tool for tracing, evaluating and experimenting with LLM and agent applications, built on OpenTelemetry.
Best for: Local debugging of LLM traces; OpenTelemetry-based stacks
- 2
Confident AI (DeepEval)
AI tool · Freemium
The cloud platform behind DeepEval, an open-source framework for unit-testing LLM outputs with ready-made metrics.
Best for: Pytest-style LLM tests; RAG evaluation metrics
- 3
LangSmith
AI tool · Freemium
LangChain's platform for tracing, evaluating and monitoring LLM apps, with a prompt hub and playground.
Best for: LangChain and LangGraph users; Dataset-based evaluation
- 4
Opik
AI tool · Open source
Comet's open-source platform for logging, evaluating and monitoring LLM apps, including prompt optimisation.
Best for: Open-source tracing and evals; Automated prompt optimisation
- 5
promptfoo
Open source · MIT · ★ 26.7k
CLI and library for testing LLM prompts and red-teaming AI apps, with declarative configs.
Best for: Developers building apps on top of LLM APIs who want repeatable prompt tests; Teams comparing several models side by side on the same prompts
- 6
Braintrust
AI tool · Freemium
An evaluation and observability platform for scoring prompts and models against datasets and monitoring production.
Best for: Systematic evals before shipping; Comparing prompt versions with scores
- 7
Helicone
AI tool · Freemium
An open-source LLM observability proxy that logs requests, costs and latency with a one-line integration.
Best for: Quick cost and usage visibility; Caching and rate limiting LLM calls
- 8
W&B Weave
AI tool · Freemium
Weights & Biases' toolkit for tracing, evaluating and comparing LLM application versions.
Best for: Teams already on Weights & Biases; Evaluation leaderboards across versions
How we pick: tools in the same category that solve the same problem, projects that name each other as alternatives, and open-source projects that describe themselves as an alternative to Langfuse. We don't take payment for placement.