AI Tools
Best AI Agent Observability Tools in 2026
When an AI agent runs, observability tools can help you inspect its prompts, tool calls, sessions, and associated costs. Compared on agent framework support, prompt and tool tracing, session replay, and trace retention, these entries also distinguish deployment options and free-plan availability.
- 01
Agenta Agenta suits teams that want to create, automate, and monitor AI agents across connected tools.
From $29/mo Free plan Open source Web · API · Self-hosted9.3 Visit Specs - 02
AgentOps From $40/mo Free plan Open source Web · API · Self-hosted9.3 Visit Specs - 03
Braintrust Braintrust is aimed at teams operating AI agents in production, from early-stage teams to enterprises.
From $249/mo Free plan Web · API · Self-hosted9.1 Visit Specs - 04
LangSmith LangSmith suits teams engineering AI agents that need evaluation, tracing, prompt work, deployment, and production monitoring.
From $39/mo Free plan Web · Windows · macOS · Linux9.1 Visit Specs - 05
LangWatch LangWatch suits AI teams shipping agents, including developers, product owners, QA, and domain experts working with evaluation workflows.
From €29/mo Free plan Open source Web · macOS · Linux · API9.1 Visit Specs - 06
Langfuse Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools.
From $29/mo Free plan Open source Web · Linux · API · Self-hosted9.0 Visit Specs - 07
Opik Opik suits teams developing applications or agents that make calls to an LLM and want tracing and evaluation across the development cycle.
From $19/mo Free plan Open source Web · Windows · macOS · Linux8.8 Visit Specs - 08
W&B Weave Weave suits teams monitoring and evaluating production AI agents, particularly those using supported frameworks and models.
From $60/mo Free plan Open source Web · Windows · macOS · Linux8.6 Visit Specs - 09 OpenLIT
OpenLIT suits teams that need LLM tracing, evaluation, prompt management, and cost tracking, especially those seeking self-hosted deployment.
Free plan Open source Web · Windows · macOS · Linux8.5 Visit Specs - 10 MLflow Tracing Free plan Open source Web · Linux · API · Self-hosted8.4 Visit Specs
- 11 PetalTrace
PetalTrace suits developers who need to inspect, compare, and replay AI agent workflows.
Free plan Web · Windows · macOS · Linux8.4 Visit Specs - 12 Arize AX
AX suits teams building AI agents that need tracing, evaluations, investigations, and experiments.
From $50/mo Free plan Web · API · Self-hosted8.3 Visit Specs - 13
Helicone Helicone suits teams routing and observing AI application requests across model providers, including teams that need self-hosting or LLM cost tracking.
From $79/mo Free plan Web · API · Self-hosted8.3 Visit Specs - 14 Lunary From $20/mo Open source Web · API · Self-hosted8.2 Visit Specs
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Fiddler AI Fiddler positions its platform for enterprises managing AI agents and predictive applications at scale.
Free plan Web · API · Self-hosted8.1 Visit Specs - 16
Laminar Laminar suits teams instrumenting AI-agent systems that need tracing, evaluations, debugging, and dashboards.
From $30/mo Free plan Web · API · Self-hosted8.1 Visit Specs - 17
Maxim AI It suits cross-functional AI teams that need to evaluate agents and monitor them in production.
From $29/mo Free plan Web · API · Self-hosted8.1 Visit Specs - 18 Traceloop Free plan Open source Web · API · Self-hosted8.1 Visit Specs
- 19 Arize Phoenix
It suits teams operating AI applications that need model, retrieval, tool, prompt, and evaluation tracing.
Free plan Web · API · Self-hosted8.0 Visit Specs - 20
SigNoz SigNoz suits engineering teams monitoring applications and infrastructure across logs, metrics, traces, and exceptions.
From $19/mo Free plan Web · iOS · Android · API8.0 Visit Specs - 21
Galileo Galileo is designed for engineers, product managers and subject matter experts building AI applications.
From $100/mo Web · API · Self-hosted7.9 Visit Specs - 22
HoneyHive HoneyHive is aimed at AI platform teams, AI engineers, domain experts, and risk or governance teams.
Free plan Web · API · Self-hosted7.9 Visit Specs - 23 Respan (formerly Keywords AI)
Respan suits teams that need to route model requests while tracing and evaluating AI workflows in production.
From $16.58/mo Free plan Web · API · Self-hosted7.8 Visit Specs - 24 Hexel Free plan API7.7 Visit Specs
- 25 LogicGaze Free plan Web · API · Self-hosted7.7 Visit Specs
Paid-from pricing gives you another point to weigh alongside cost tracking. W&B Weave, PetalTrace, and SigNoz are among the names to compare for the visibility features you need. Consider what you want to review during and after an agent session, which frameworks matter to your work, and how long traces should remain accessible. The listed criteria make those trade-offs easier to examine.