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📖 The AI Tool Bible

Best AI tools for observability

19 tools in the Evaluation category, filtered to observability.

All Evaluation →
BR

Braintrust

Featured
Evaluation · Platform (any LLM)
8.9

Eval, monitor, and improve AI products end-to-end.

Freemium· Starter: $0 · Pro: $249 · Enterprise: Custom pricingevalsmonitoring
LA

LangSmith

Evaluation · Platform (any LLM)
8.7

LangChain's eval + observability platform.

Freemium· Developer: $0 · Plus: $39 · Enterprise: Custom pricingLLM tracingevals
HE

Helicone

Evaluation · Platform (any LLM)
8.3

Open-source LLM observability — one-line proxy install.

Freemium· Free 100k req/mo; Pro from $25/moobservabilitycost tracking
AG

AgentOps

Agents · Multi-model
8.2

Observability and debugging platform purpose-built for AI agents, with time-travel replay and cost tracking across 400+ LLMs.

Freemium· Free up to 5,000 events; Pro from $40/mo; Enterprise customagent-observabilityllm-tracing
AA

Arize AI

Evaluation · Multi-model
8.2

Enterprise observability and evaluation platform for LLM agents and generative AI applications.

Freemium· AX Free: Free · AX Pro: $50 · AX Enterprise: Customllm-observabilityagent-evaluation
HO

HoneyHive

Evaluation · Multi-model
8.1

OpenTelemetry-native observability and evaluation platform for LLM agents in production.

Freemium· Free tier available; paid/enterprise tiers via salesagent-observabilityllm-evaluation
TR

TruLens

Evaluation · Multi-model (LLM-as-judge)
8.1

Open-source evaluation and tracing framework for LLM apps and agents, built on OpenTelemetry.

Free· Free, open source (Apache-licensed Python package)llm-evaluationrag-evaluation
WB

W&B Weave

Evaluation · Multi-model
8.1

Production observability, tracing, and evaluation for LLM and agent systems from the Weights & Biases stack.

Freemium· Free tier available; paid and enterprise plans via W&Bllm-tracingagent-observability
LA

Langfuse

Evaluation · Model-agnostic
7.3

Open-source LLM observability, prompt management, and evaluation in one platform.

Freemium· Free self-host & Hobby tier; Core $29/mo, Pro $199/mo, Enterprise $2,499/mollm-observabilityprompt-management
OP

Opik

Evaluation · Multi-model
7.3

Open-source LLM observability and evaluation platform for debugging and monitoring AI agents in production.

Freemium· Free open-source self-host; free Cloud tier (no card); Enterprise contact salesllm-tracingagent-evaluation
AR

Arthur

Evaluation · Multi-model
7.1

Open-source toolkit for testing, tracing, and monitoring production AI agents.

Freemium· Free: $0/mo · Premium: $60/mo · Enterprise: Customagent-evaluationprompt-management
FA

Fiddler AI

Evaluation · Fiddler Centor (proprietary evaluators)
7.1

Enterprise AI observability and guardrails platform for monitoring agents, LLMs, and ML models in production.

Enterprise· Free: Free · Developer: $0.002 per trace · Enterprise: Contact salesllm-observabilityagent-monitoring
PH

Phoenix

Evaluation · Multi-model
7.0

Open-source LLM and agent observability platform with tracing, evals, and experimentation built on OpenTelemetry.

Freemium· AX Free: Free · AX Pro: $50 · AX Enterprise: Customllm-tracingagent-debugging
SU

Superwise

Evaluation · Multi-model
7.0

Agentic management platform for runtime guardrails, policy enforcement, and observability across LLM agents.

Freemium· Starter: Free · Pro+: ? · Enterprise: ?llm-guardrailsai-governance
AG

Agenta

Evaluation · Multi-model
6.9

Open-source LLMOps platform for prompt engineering, evaluation, and observability in one workspace.

Freemium· Hobby: $0 forever · Pro: $29 /month · Business: $299 /month · Enterprise: Custom · Open source: Free foreverprompt-engineeringllm-evaluation
CL

ClickHouse

RAG

The open-source columnar database powering real-time analytics — and, increasingly, LLM observability and RAG backends.

Freemium· Open-source self-managed: free. ClickHouse Cloud: from $50/month (usage-based on compute + storage, AWS/GCP/Azure). Enterprise tier available with dedicated support and BYOC options.LLM trace and cost analyticsRAG retrieval with hybrid vector + metadata filters
LM

Lagotto Meter

Evaluation

Measure the gap between what your site claims and what an AI agent actually finds

Free· Free (currently in public beta)AI-visibility audit of a landing pageFact-vs-claim gap analysis for marketing copy
LA

LangWatch

Evaluation · Model-agnostic; supports OpenAI, Anthropic, AWS Bedrock, Azure OpenAI, Vertex AI, and any OpenTelemetry-instrumented LLM

Simulation-based testing, evaluation, and observability for LLM agents

Freemium· Developer: €0 · Growth: €29/ core-seat / month · Enterprise: CustomLLM agent regression testing in CIRAG answer-quality evaluation
NE

Netron

Evaluation

Visualizer for neural network, deep learning, and machine learning models

Free· Free and open-source (MIT license). Available as a web app, desktop app (macOS/Linux/Windows), and Python package at no cost.ONNX model inspectionPyTorch checkpoint debugging