phoenix vs opik
LLM application tracing and evaluation compared
phoenix and opik both help teams trace, evaluate, and troubleshoot LLM applications, including retrieval and agent workflows. phoenix emphasizes OpenTelemetry-based tracing and cross-framework evaluation, while opik also highlights production monitoring, CI/CD testing, and a choice of self-hosting or Comet Cloud.
phoenix: Observe and Evaluate AI Applications
Arize Phoenix is a self-hosted platform for tracing, evaluating, and troubleshooting LLM applications. It helps AI engineers inspect runtime behavior and test changes to prompts, models, and retrieval.
opik: Trace, Evaluate, and Monitor LLM Applications
Opik is Comet’s open-source platform for tracing, evaluating, and monitoring LLM applications, RAG systems, and AI agents. It combines framework integrations, datasets and experiments, prompt tools, and production dashboards, with cloud and self-hosted options.
| phoenix | opik | |
|---|---|---|
| Language | Python | Python |
| License | NOASSERTION | Apache-2.0 |
| Stars | 11.7k | 22.8k |
| Forks | 1.2k | 1.9k |
| Last analyzed | Oct 3, 2026 | Oct 22, 2026 |
Key differences
- phoenix uses OpenTelemetry-based traces and OpenInference instrumentation; opik supports its SDK, framework integrations, and OpenTelemetry.
- opik lists production monitoring for feedback scores, token usage, and online evaluations, plus PyTest integration for CI/CD; phoenix focuses on tracing, experiments, and evaluation.
- phoenix reports its license as NOASSERTION in repository metadata and describes Elastic License 2.0 in its README; opik reports Apache-2.0.
- phoenix is self-hosted, with local, container, or cloud deployment options; opik can be self-hosted or used through Comet Cloud.
- Both list Python as a language; opik also offers a TypeScript SDK.
- The provided metadata lists 22.4k stars and 1.8k forks for opik, compared with 11.7k stars and 1.2k forks for phoenix.
Choose phoenix if you…
- need OpenTelemetry-based tracing with OpenInference instrumentation across frameworks and providers.
- want to create versioned datasets and compare prompt, model, or retrieval changes in experiments.
- prefer a self-hosted option and are prepared to operate its environment.
Choose opik if you…
- need production monitoring for traces, feedback, token usage, or online evaluation results.
- want to test LLM pipelines in CI/CD using the PyTest integration.
- prefer a choice between self-hosting and Comet Cloud, or need the Python and TypeScript SDKs.
Compare the numbers side by side, or add more projects
This comparison is generated with AI from the OSRepos analyses of both projects. Always check each project's repository and documentation before choosing.