Opik

Overview

Opik is an observability and evaluation platform for teams building LLM applications and agents. It is a strong fit for teams that want to trace behavior, test prompts and agents, and monitor production in one workflow, with a choice of cloud or self-hosting. Its breadth is useful, but cloud span limits make workload size an important buying consideration.

Key features

Opik captures and visualizes agent actions, with trace annotation and audit logs for investigating behavior. More than 30 evaluation metrics cover outcomes such as answer relevance, context precision, task completion, and hallucination. That gives teams a broad starting point for evaluating applications, though they will still need to choose criteria suited to their own tasks.

Production monitoring can evaluate traces in real time, alert on failed criteria, and track token usage and model costs. Test Suites add pass/fail assertions, the Agent Playground supports end-to-end tests, and the Prompt Optimizer offers six algorithms. Together, these features link development checks with production oversight rather than treating evaluation as a pre-release exercise.

The core observability and evaluation feature set is open source and can run locally. Opik includes a REST API and Python client, and lists Python and TypeScript SDKs. More than 40 integrations span AI frameworks, model providers, and gateways; named examples include LangChain, OpenAI, Google ADK, and LangGraph. This makes it relevant to teams working across established AI tooling, while the self-hosted option gives teams a way to run the core code themselves.

Pricing

Opik uses a freemium model. Free Cloud costs nothing (billed $0) and allows up to 10 team members, 25,000 spans per month, and 60-day data retention. That is a substantial starting allowance for development and testing, but teams with higher trace volume or a need for longer retention may outgrow it.

Open Source costs nothing (billed $0) and provides the full AI observability and agent testing feature set on the same codebase as the hosted versions, self-hosted. It avoids cloud plan span caps, but teams choosing this route take on running the deployment themselves.

Pro Cloud costs $19 a month (billed $19 per month). It raises the ceiling to up to 50 team members and 100,000 spans per month, retains data for 60 days, and allows customizable span limits and retention periods. That is the more practical cloud tier for teams beyond the free allowance, though its monthly price and baseline span cap still need to fit anticipated usage. Community and self-service support are available across plans; Pro also includes email support.

Enterprise has custom pricing, unlimited team members, custom usage plans, flexible deployments, dedicated support, and SLAs. Its listed security and compliance coverage includes SSO, SOC 2, ISO 27001, ISO 9001, HIPAA, and GDPR, making it the tier for organizations that need these controls and support terms. Free trial availability is indicated, but no trial duration is stated.

Platforms

Opik is available through an API, Linux, the web, and self-hosted deployment. That mix suits teams that want a hosted interface or prefer to run the core platform locally.

Who it's for

Opik is best for teams building applications or agents that call an LLM and need connected tracing, evaluation, testing, and production monitoring. Its free plans suit development and testing; teams with larger workloads should compare their expected spans and retention needs with Pro Cloud's limits or consider self-hosting. It is a less natural fit for users who do not need an LLM-focused workflow or want cloud usage without span ceilings.

Pros and cons

• Pros: Tracing, evaluation, test tooling, and production monitoring share one platform, helping teams follow issues across stages.
• Pros: The open-source core can be self-hosted, while Free Cloud offers up to 10 members and 25,000 monthly spans.
• Pros: More than 40 integrations and Python and TypeScript SDKs support a range of AI development stacks.
• Cons: Free Cloud is capped at 25,000 spans per month and 60-day retention, which may constrain growing workloads.
• Cons: Pro Cloud starts at $19 a month and its base allowance is 100,000 spans per month; teams with larger needs must use customizable limits or consider Enterprise.
• Cons: Enterprise requires custom pricing, so its cost cannot be weighed against a fixed monthly rate.

Alternatives

OpenLIT is worth considering when unlimited self-hosted usage, users, and projects matter more than Opik's integrated plan structure; its OSS plan is free and includes community support through GitHub.

W&B Weave may suit teams that prefer its free allowance of 1 GB per month of Weave data ingestion and 5 GB per month of storage alongside evaluations, tracing, and scorers.

Agenta is an alternative for a smaller team whose needs fit its free Hobby plan: two team members, 5,000 agent runs per month, 20 evaluations per month, and one-week trace retention.

Arize AX may fit teams that can work within a free SaaS plan with 25,000 trace spans per month, 1 GB ingestion per month, and 15-day retention, alongside unlimited users and evaluations.

Braintrust offers a free Starter plan with 1 GB of processed data, 10,000 scores, 14-day retention, and unlimited users, projects, and datasets; consider it if those limits better match your usage.

PetalTrace is another free option with API, Linux, macOS, self-hosted, web, and Windows platforms.

SigNoz is an alternative with a free self-hosted community plan that leaves infrastructure, storage, scaling, upgrades, and backups to the user.

Fiddler AI is another freemium alternative.

Browse AI Agent Observability Tools, Machine Learning Model Monitoring Software, AI LLM Observability Tools, AI Agent Evaluation Tools, LLM Observability Tools, and AI LLM Evaluation Tools to compare across categories.

Verdict

Choose Opik if your team needs an end-to-end workflow for tracing, evaluating, testing, and monitoring LLM applications, especially if self-hosting matters. Its combination of open-source deployment and broad evaluation and monitoring tools is the central appeal. Look elsewhere if your expected cloud span volume or retention needs do not fit the plan limits, or if you want a published Enterprise price.