Best LLM Observability Products in 2026

Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.

Key Langfuse features:

User-Friendly Interface Integration Capabilities Comprehensive Analysis Tools

Open Source

A habit and interest tracker for everything you care about. Set your own cadence, daily to monthly, and streaks follow your schedule. Buy once for $21, no subscription.

Key EatAWhale features:

Cost Per Session Cadence You Choose Adjustable Pressure One Purchase, Every Platform

Try for free freemium $21 / One-off Sponsored

Build and deploy LLM applications with confidence.

Key LangSmith features:

Enhanced Workflow Integration User-Friendly Interface Advanced Language Model Support Comprehensive Analytics

Rapidly ship AI without guesswork.

Key Braintrust.dev features:

Decentralization Lower Fees Token Incentives Community Governance

See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.

Key Datadog features:

Comprehensive Monitoring Integration Ecosystem Scalability Real-Time Data

freemium $15 / Monthly (per host)

Arize Phoenix: Open Source AI Development Platform.

Key Arize Phoenix features:

Open source and free to self-host Built on OpenTelemetry and OpenInference Comprehensive LLM observability and evaluation Easy local setup and notebook-friendly

Open Source free

Continuously improve AI agents with agent observability, evaluation, tracing, and experimentation.

Key Arize features:

Comprehensive ML observability Strong LLM observability and evaluation Open-source option with Phoenix Powerful root-cause analysis

Open Source freemium

Build production-grade & reliable AI apps with Portkey.

Key Portkey features:

Ease of Use Integration Capabilities Scalability Customization

One OpenAI-compatible endpoint for every major AI provider. Extract structured data from 20+ document formats. Track tokens, costs, grounding.

Key 2kw.ai features:

LLM Gateway Document Data Extraction Cost Tracking

paid Free Trial €99 / Monthly (Performance plan, 7-day free trial)

Observability, evals and guardrails for AI agents.

Key Block Convey features:

Agent Observability Quality Evaluation Guardrails for AI Safety Agent and end-user intelligence

freemium $20 / Monthly (Builder Plan enables solo builders monitor their AI in real time)

Know which customers are quietly unprofitable.

Key Weckr features:

Margin per customer Spending caps that enforce Runaway agent detection Cost per feature

freemium $49 / Monthly (Pro, up to 1M requests)

Next-gen observability for modern systems.

Key Atatus features:

Application performance monitoring Analytics and Reporting Root Cause Analysis Website monitoring

paid Free Trial $49 / Monthly

OpenTelemetry-native observability for AI agents and LLM applications. Trace model calls, investigate failures, and monitor token usage, estimated cost, and latency.

Key Telemetry.dev features:

Likely focus on developer telemetry Potential for fast setup Centralized visibility

Open Source

Free crawler checks and selected OpenAI answer reviews from $9/month.

freemium $9 / Monthly (Pro)