Weave suits teams building or operating production AI agents that need tracing, evaluations, interaction monitoring, or prompt comparisons.
Free plan Free trial Open source From $60 a month iPhone & iPadWebWindowsMacLinuxAPI+1
Best AI LLM Observability Tools 2026
Facts read 29 Sep 2026 – 21 Oct 2026
When LLM-powered applications are in the picture, observability tools help you inspect request traces, investigate failures, and assess outputs and costs. Compare LLM trace capture with failure tracking and latency metrics to understand what you can monitor. Output evaluations and token cost tracking add ways to examine results and usage. Free-plan access, retention on that plan, and the paid starting price may also shape your choice. Arize AX, Langfuse, and Opik are among the options to consider, alongside W&B Weave and Agenta. Use the listed criteria to decide which monitoring signals and evaluation details matter for the applications you work with.
The standings: top 10
| Name | In a line | Record score | Price from | Try it free | Runs on | Facts read |
|---|---|---|---|---|---|---|
| 01 W&B Weave | Weave suits teams building or operating production AI agents that need tracing, evaluations, interaction monitoring, or prompt comparisons. | 6.2 | $60 a month | Free plan | iPhone & iPad, Web, Windows, Mac | 20 Oct 2026 |
| 02 Opik | Opik suits teams developing applications or agents that call an LLM and need to inspect, evaluate, and monitor their behavior. | 6.1 | $19 a month | Free plan | Web, Windows, Mac, Linux | 21 Oct 2026 |
| 03 Langfuse | Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools. | 5.7 | $29 a month | Free plan | Web, Linux, API, Self-hosted | 15 Oct 2026 |
| 04 LangWatch | LangWatch suits AI teams working on agents, including developers, product owners, QA, and domain experts involved in evaluation workflows. | 5.7 | €29 a month | Free plan | Web, Mac, Linux, API | 21 Oct 2026 |
| 05 Agenta | Agenta suits teams that want to create and operate AI agents across work tools, with cloud or self-hosted deployment options. | 5.5 | $29 a month | Free plan | Web, API, Self-hosted | 14 Oct 2026 |
| 06 OpenLIT | OpenLIT suits developers who want to observe LLM applications, prompts, evaluations, and costs. | 5.5 | Free plan | Free plan | Web, Windows, Mac, Linux | 14 Oct 2026 |
| 07 LangSmith | LangSmith suits teams developing AI agents that need evaluation, prompt tools, tracing, and production monitoring. | 5.3 | $39 usage-based | Free plan | Web, Windows, Mac, Linux | 15 Oct 2026 |
| 08 Maxim AI | It is designed for cross-functional AI teams, including product managers who want to define and analyze evaluations without code and developers who use SDKs, a CLI, or… | 5.2 | $29 a month | Free plan | Web, API, Self-hosted | 2 Oct 2026 |
| 09 Braintrust | Braintrust is intended for teams running AI agents in production, from early-stage projects to enterprise deployments. | 5.0 | $249 a month | Free plan | Web, API, Self-hosted | 15 Oct 2026 |
| 10 Helicone | It suits teams building or operating AI applications that need provider routing, request tracing, or cost visibility. | 5.0 | $79 usage-based | Free plan | Web, API, Self-hosted | 1 Oct 2026 |
02
Opik
Opik suits teams developing applications or agents that call an LLM and need to inspect, evaluate, and monitor their behavior.
WebWindowsMac+3 Record6.1 Visit
03
Langfuse
Langfuse suits teams building AI agent applications that need tracing, prompt management, and evaluation tools.
WebLinuxAPI+1 Record5.7 Visit
04
LangWatch
LangWatch suits AI teams working on agents, including developers, product owners, QA, and domain experts involved in evaluation workflows.
WebMacLinux+2 Record5.7 Visit
05
Agenta
Agenta suits teams that want to create and operate AI agents across work tools, with cloud or self-hosted deployment options.
WebAPISelf-hosted Record5.5 Visit
6
OpenLIT
WebWindowsMac+3 Free plan Record5.5 Visit OpenLIT suits developers who want to observe LLM applications, prompts, evaluations, and costs.
7
LangSmith
WebWindowsMac+3 $39 usage-based Record5.3 Visit LangSmith suits teams developing AI agents that need evaluation, prompt tools, tracing, and production monitoring.
8
Maxim AI
WebAPISelf-hosted $29 a month Record5.2 Visit It is designed for cross-functional AI teams, including product managers who want to define and analyze evaluations without code and developers who use SDKs, a CLI, or…
9
Braintrust
WebAPISelf-hosted $249 a month Record5.0 Visit Braintrust is intended for teams running AI agents in production, from early-stage projects to enterprise deployments.
10
Helicone
WebAPISelf-hosted $79 usage-based Record5.0 Visit It suits teams building or operating AI applications that need provider routing, request tracing, or cost visibility.
12
Confident AI
WebAPISelf-hosted $200 a month Record4.8 Visit It is designed for engineers, QA teams, product managers, subject-matter experts, and annotators working on AI quality, evaluation, or production monitoring.
14
Respan (formerly Keywords AI)
WebAPISelf-hosted $199 a year Record4.8 Visit Respan suits startup and enterprise teams tracing workflows, evaluating agent behavior, and monitoring production AI systems.
16
Fiddler AI
WebAPISelf-hosted Free plan Record4.7 Visit Fiddler AI is aimed at enterprises managing AI agents and predictive applications at scale, including teams that need monitoring, guardrails, and audit evidence.
17
Portkey
WebAPISelf-hosted $49 a month Record4.6 Visit Portkey suits teams building or operating applications that use multiple AI models and need routing, activity monitoring, and prompt management.
18
PromptLayer
WebAPISelf-hosted $49 a month Record4.6 Visit PromptLayer suits engineers and domain experts who need to manage prompts, evaluate changes, and observe AI product activity together.
19
Arize AX
WebAPISelf-hosted $50 a month Record4.4 Visit Arize AX suits teams working to observe, evaluate, and improve AI agents in production.
20
Galileo
WebAPISelf-hosted $100 a month, billed yearly Record4.4 Visit Galileo is designed for engineers, product managers, and subject matter experts building AI applications.
21
HoneyHive
WebAPISelf-hosted Free plan Record4.4 Visit It suits AI platform teams, AI engineers, domain experts, and risk and governance teams that need production agent visibility.
22
Arize Phoenix
WebAPISelf-hosted Free plan Record4.3 Visit Phoenix suits teams that need to inspect AI application traces and compare evaluation results across versions.
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