Best Observability in 2026
11 listings. Featured first, then A to Z. Head-to-head comparisons
Arize Phoenix
AI observability and evaluation you can self-host
Braintrust
Evals, logging and prompt tooling for AI products
Datadog LLM Observability
LLM traces inside Datadog
Helicone
Open-source LLM observability through a proxy or SDK
Langfuse
Open-source LLM observability, evals and prompt management
LangSmith
Tracing, evals and deployment from the LangChain team
OpenLLMetry
OpenTelemetry instrumentation for LLM apps
Opik
Open-source LLM tracing and evals from Comet
PostHog LLM analytics
LLM traces next to product analytics
Pydantic Logfire
OpenTelemetry observability from the Pydantic team
Weights & Biases Weave
Tracing and evaluation for AI applications