18.7
W&B Weave provides observability and continuous improvement tools for production AI agents.
Free planOpen sourceiOSWebAPI
Best LLM Observability Tools in 2026
When you need visibility into model and application behavior, LLM observability tools offer different tracing, evaluation, and management features to compare. Check agent tracing, LLM tracing, and retrieval tracing to see which parts of a workflow are represented; then weigh LLM evaluations and prompt management. Token cost tracking can help you compare cost-visibility features, while deployment options, free-plan…
28.4
Opik helps teams building applications or agents that call an LLM log actions and evaluate behavior through development, testing, and production.
Free planOpen sourceWebAPILinux
38.3
Evidently AI evaluates, tests, and monitors machine-learning models, LLMs, RAG applications, and AI agents.
Free planOpen sourceWebAPILinux
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Langfuse
Langfuse is an open-source AI engineering platform for teams debugging, analyzing, and iterating on AI agent applications.
Free planOpen sourceWebAPILinuxSelf-hosted8.2From $29 a month - 5
LangWatch
LangWatch is an AI agent engineering platform for teams preparing agents for production.
Free planOpen sourceWebAPILinuxmacOS8.2From €29 a month - 6
LangSmith
LangSmith is a platform for building, evaluating, deploying, monitoring, and improving AI agents.
Free planWebAPILinuxmacOS8.0$39 usage-based - 7
AgentOps
AgentOps is a developer platform for building AI agents and LLM applications.
Free planOpen sourceWebAPISelf-hosted7.8From $40 a month - 8
Promptfoo
Promptfoo helps developers and enterprises evaluate prompts and test AI applications for security risks.
Free planOpen sourceWebAPILinuxmacOS7.8Free plan - 9
Braintrust
Braintrust is an observability platform for teams improving AI agents that run in production.
Free planWebAPISelf-hosted7.7From $249 a month - 10
OpenLIT
OpenLIT is an open-source Agent Harness Engineering platform for LLM tracing, evaluations, prompt management and cost tracking, built on OpenTelemetry.
Free planOpen sourceWebAPILinuxmacOS7.7Free plan - 11
Giskard
Giskard is a freemium platform for finding security and quality problems in AI agents before production use.
Free planOpen sourceWebAPILinuxSelf-hosted7.6Free plan - 12
TruLens
TruLens is a free, open-source Python SDK for tracing and evaluating AI agents, RAG applications, MCP apps, and summarization systems.
Free planOpen sourceAPISelf-hosted7.2Free plan - 13
Lunary
Lunary is an AI platform for enterprises and developers building chatbots or other applications powered by large language models.
Open sourceWebAPISelf-hosted7.1From $20 a month - 14
Maxim AI
Maxim AI is an evaluation and observability platform for simulating, assessing, and monitoring AI agents.
Free planWebAPISelf-hosted7.0From $29 a month - 15
Confident AI
Confident AI is an AI quality platform for evaluating application changes during development and monitoring AI applications in production.
Free planWebAPISelf-hosted6.9From $200 a month - 16
Galileo
Galileo is an observability, evaluation, and guardrail platform for generative AI and agentic applications.
Free planWebAPISelf-hosted6.9From $100 a month - 17
Helicone
Helicone is a platform for routing, debugging, and analyzing AI applications.
Free planWebAPISelf-hosted6.9From $79 a month - 18
Arize AX
Arize AX is a platform for improving AI agents by turning production behavior into issues, investigations, evaluations, and experiments.
Free planWebAPISelf-hosted6.8From $50 a month - 19
Laminar
Laminar is an open-source observability and debugging platform for AI agents, designed around OpenTelemetry.
Free planWebAPISelf-hosted6.8From $30 a month - 20
Parea AI
Parea AI is a platform for experiment tracking, observability, and human annotation for teams building LLM applications for production.
Free planWebAPISelf-hosted6.8From $150 a month - 21
Respan (formerly Keywords AI)
Respan (formerly Keywords AI) is an AI gateway with tools for observing, evaluating, and security testing AI systems.
Free planWebAPISelf-hosted6.7From $199 a year - 22
Fiddler AI
Free planWebAPISelf-hosted6.4Free plan - 23
HoneyHive
HoneyHive is an agent observability platform for teams that want to observe, evaluate, and improve AI agents in production.
Free planWebAPISelf-hosted6.4Free plan - 24
Arize Phoenix
Arize Phoenix helps teams trace, evaluate, debug, and improve AI applications.
Free planWebAPISelf-hosted6.3Free plan - 25
OpenLLMetry
OpenLLMetry is free, Apache-2.0 software for monitoring and debugging LLM application execution.
Free planWebAPISelf-hosted6.1Free plan