Opik vs Langfuse: open-source LLM observability compared

Opik and Langfuse are both open-source LLM observability platforms covering tracing, evaluation and prompt management, per their own sites as checked 2026-10-14. The documented distinction: Opik's site stresses prompt optimization algorithms and test suites built from traces, while Langfuse's stresses a ClickHouse-backed tracing platform, OpenTelemetry support and a stated free tier.

Quick comparison

The row order is editorial, not a ranking of quality. It follows the order of the query.

How the options differ

Product focus

Opik describes itself as a platform to understand what an LLM application is doing, measure how well it works, and improve it. Its site lists tracing of every LLM call, tool invocation and agent step, plus evaluation metrics such as hallucination and context recall.

Opik also lists optimization: its site says it offers six optimization algorithms that generate and test prompts for steps in an agent. Langfuse's site does not mention an equivalent prompt optimization feature in the excerpts we read.

Langfuse frames its product as a loop connecting tracing, monitoring, datasets, experiments and evaluation. Its site lists hierarchical traces, LLM-as-a-judge and human review, prompt deployments and rollbacks, side-by-side model comparison, and dashboards with automated alerts.

Agent and IDE surfaces

Both sites describe coding-agent access. Opik says its MCP server works with Claude Code, Cursor, VS Code Copilot, Codex and opencode, letting users read traces, score outputs, save prompts and run experiments from chat.

Langfuse lists an in-app Assistant, a SKILL.md skill, a CLI and an MCP server. It says the CLI offers full API access for scripts and CI/CD, and that MCP gives IDE agents structured access to prompts and traces.

Deployment and architecture

Opik's site says it can be deployed on your own infrastructure with Docker locally or Kubernetes at scale. It also says cloud, open-source and enterprise versions include the full feature set and run on the Comet platform.

Langfuse's site lists a ClickHouse OLAP database, async ingestion via a Redis queue, and S3/blob storage for large payloads. It states "Self-host for free" under its open-source section. Opik's sources describe self-hosting but do not state its cost.

Integrations

Opik's site says it works with OpenAI, Anthropic, LangChain and 50+ other providers and frameworks. Langfuse's site says it works with any language and framework supporting OTel instrumentation, and lists 100+ integrations. These are vendor claims; we did not verify any integration.

License

The Opik repository reports Apache-2.0 through the GitHub API. For Langfuse, the GitHub API does not report a recognized license for the repository, while the Langfuse site says all product features are MIT licensed. We could not reconcile this from the cited sources, so check the repository's license files before relying on either statement.

How we compared

We read four primary sources: the comet-ml/opik and langfuse/langfuse GitHub repository metadata, the Opik docs page and the Langfuse homepage. Everything was checked on 2026-10-14.

We did not install or run either tool, benchmark performance, or verify any vendor claim such as adoption figures or integration counts. Vendor numbers on the Langfuse site (users, installs, events processed) are the vendor's own statements and are not used to rank the tools.

Limitations

The sources do not state Opik's pricing, hosted-tier limits or enterprise terms. They do not state Langfuse's paid-tier prices either; only a free tier is given.

The sources do not provide a head-to-head feature comparison, latency or cost measurements, or migration guidance between the two. Neither source says how the tools handle data residency for hosted plans beyond what is quoted above. Release-level changes are covered in separate launch notes: Opik 2.2.97 and Langfuse v4.57.0.

For more tools in this space, see the Opik hub, the Langfuse hub and the Agent infra category, or read the related Langfuse v4.57.0 launch note.