Free and open first
Best Llm Monitoring in 2026
LLM monitoring tools help you inspect and assess language-model applications. This category covers tracing, evaluation support, deployment options, trace retention, alerts, and supported LLM providers.
- 26 apps
- Research read 7 Oct 2026
- How the order is worked out
- 1
Agenta
Free plan Open source APISelf-hostedWebAgenta combines agent-building, automation, and run observability, with both cloud and self-hosted options.
- 2
AgentOps
Free plan Open source APISelf-hostedWebAgentOps brings tracing, replay, audit trails, and cost monitoring together for agent applications, with broad framework and provider integrations.
- 3
Future AGI AI Evaluation SDK
Free plan Open source APILinuxMac+3Future AGI brings evaluation, tracing, and simulation together for teams building AI agents, with several deployment options.
- 4
Langfuse
Free plan Open source APILinuxSelf-hosted+1Langfuse brings tracing, prompt workflows, and evaluation features into one AI engineering platform, with both hosted and self-hosted options.
- 5
LangWatch
Free plan Open source APILinuxMac+2LangWatch brings agent simulation, evaluation, tracing, and deployment options together for teams working toward production.
- 6
OpenLIT
Free plan Open source APILinuxMac+3Choose OpenLIT if you want LLM tracing, evaluations, prompt tools, and cost tracking, with the option to self-host under an Apache 2.0 license.
- 7
Opik
Free plan Open source APILinuxMac+3Opik brings tracing, evaluation, testing, and production monitoring into one platform, with both cloud and self-hosted options.
- 8
W&B Weave
Free plan Open source APIiPhoneLinux+4W&B Weave brings tracing, evaluation, monitoring, and safety scoring together for production AI agents.
- 9
Traceloop
Free plan Open source APISelf-hostedWebTraceloop brings tracing, evaluation, and release checks together, with OpenLLMetry available for exporting observability data.
- 10
TruLens
Free plan Open source APISelf-hostedTruLens offers tracing, evaluation, and version comparison for AI applications, with customizable metrics and self-hosted storage options.
- 11
Arize AX
Free plan APISelf-hostedWebArize AX combines tracing, evaluations and experiments with tools for investigating agent failures.
- 12
Arize Phoenix
Free plan APISelf-hostedWebPhoenix brings tracing, evaluation, prompt inspection, and dataset experiments to AI application teams. It is free and open source, with deployment choices and usage management left to users.
- 13
Braintrust
Free plan APISelf-hostedWebBraintrust combines production trace inspection with dataset evaluations and prompt iteration.
- 14
Galileo
Free plan APISelf-hostedWebGalileo combines evaluation, observability, and guardrails with several deployment options and developer interfaces. Check the trace allowance and SSO availability against your deployment needs.
- 15
Helicone
Free plan APISelf-hostedWebHelicone brings routing and observability tools together, with a free tier and self-hosting options. Its maintenance-mode status is worth weighing when considering it for a new deployment.
- 16
LangSmith
Free plan APILinuxMac+3LangSmith combines agent evaluation with prompt tools and observability, including cost and trajectory tracking.
- 17
HoneyHive
Free plan APISelf-hostedWebHoneyHive covers trace inspection, evaluations, live monitoring, and version experiments for AI agents. Teams should compare the free plan’s limits with their event volume and retention needs.
- 18
Laminar
Free plan APISelf-hostedWebChoose Laminar if you need OpenTelemetry-native tracing and debugging for AI agents, with evaluations and cloud or self-hosted deployment options.
- 19
Portkey
Free plan APISelf-hostedWebPortkey brings model access, prompt management, and activity monitoring under one platform. Review the plan's log retention, deployment, and support terms against your team's requirements.
- 20
Cognifity Verdict
Free plan LinuxMacWeb+1 - 21
Athina
Free plan Web - 22
Datadog LLM Observability
Free plan Web - 23
Observe
Free trial APILinuxMac+2Observe combines telemetry collection, distributed tracing, integrations, and AI-assisted incident work in one platform.
- 24
Bifrost AI Observability
Free plan - 25
MLflow AI Monitoring
Free plan Web
#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price
Compare the free plan, paid starting price, and trial terms before choosing. If you need code you can read or change, check the licence. Confirm whether web, API, self-hosted, Linux, macOS, or Windows access fits your setup.
Questions
Do LLM monitoring tools have free plans?
Yes. The list includes tools with free plans, including Agenta, AgentOps, Arize Phoenix, and Galileo.
Are any LLM monitoring tools open source?
Open-source code is available from tools in this category. Check the licence for the tool you are considering.
Can I try a paid LLM monitoring tool before paying?
Yes. A free trial is offered by tools on the list. Atatus LLM Observability and Bifrost AI Observability list 14-day trials.
What platforms do these tools support?
Platforms listed for tools in this category include web, API, self-hosted, Linux, macOS, and Windows.
What should I compare between LLM monitoring tools?
Compare free plan, paid starting price, LLM tracing, evaluation support, deployment options, trace retention, alerts, and LLM providers.