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Opik (Comet) vs Langfuse
Quick verdict
Key difference: Langfuse is OpenTelemetry-native (no lock-in) while Opik (Comet) uses a proprietary SDK.
Side-by-side comparison from the Agent Observability Index: licensing, self-hosting, pricing model and integrations — no vendor copy, primary sources linked.
| Opik (Comet) | Langfuse | |
|---|---|---|
| One-liner | Open-source LLM evaluation and tracing platform from Comet, combining trace logging, eval metrics and CI-friendly test suites. | Open-source (MIT) LLM engineering platform combining tracing, prompt management, evals and datasets, widely used as the default self-hosted observability stack. |
| Category | Observability & Tracing | Observability & Tracing |
| OpenTelemetry-native | No | Yes |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Pricing model | freemium | freemium |
| Pricing notes | Apache-2.0 self-host free; Comet cloud free tier + paid plans | Free Hobby tier (50k units/mo); Core $29/mo, Pro $199/mo, unlimited users on paid tiers; MIT core fully self-hostable |
| Frameworks | openai-sdk, langchain, llamaindex, litellm, dspy, haystack | langchain, openai-sdk, llamaindex, litellm, opentelemetry, vercel-ai, haystack |
| GitHub stars | 19.6k | 29k |
| Maturity (GitHub signal) | 100/100 (Mature) | 90/100 (Mature) |
| Funding / ownership | Backed by Comet ML ($50M Series B, 2021) | YC W23; $4M seed (Lightspeed, La Famiglia) |
How to choose
- Both link to primary pricing sources below — verify current tiers before committing; this market shifts monthly.
Sources: Opik (Comet) · Langfuse
Frequently asked questions
Is Opik (Comet) or Langfuse open source?
Opik (Comet): Yes. Langfuse: Yes.
Can Opik (Comet) and Langfuse be self-hosted?
Opik (Comet): Yes. Langfuse: Yes.
Opik (Comet) vs Langfuse: which should I choose?
Key difference: Langfuse is OpenTelemetry-native (no lock-in) while Opik (Comet) uses a proprietary SDK.