Best LangSmith alternatives

Open-source LLM observability and evaluation platform built on OpenTelemetry, with tracing, datasets, experiments and prompt tooling.

Open-source LLM observability platform for tracing, evaluating, and debugging prompts and agent runs, self-hostable or available as a managed cloud service.

Weights & Biases toolkit for tracing, evaluating and monitoring LLM applications, with automatic call logging and scorers.

Evaluation-first platform for LLM applications, treating prompt and model changes like code changes that need regression tests before shipping.

Open-source LLM observability proxy that sits between your app and a model provider, logging requests, costs, and latency with a one-line integration change.