LLMOps and observability
Opik: review, pricing, data and alternatives
Opik lets teams developing applications that use models record execution steps and compare experiments. It evaluates responses using automated criteria, monitors production errors and tracks model call costs. A free tier exists; the first paid plan costs $19 per month. Access and transparency score: 83/100, #3 of 18 in its category.
What is Opik?
Opik lets teams developing applications that use models record execution steps and compare experiments. It evaluates responses using automated criteria, monitors production errors and tracks model call costs.
According to its documentation, Opik lets you:
- record the steps of an application using models
- compare experiment results
- evaluate responses using automated criteria
- monitor errors in production
- track the costs of model calls
We file it under LLMOps and observability, the category of tools to evaluate, monitor and debug AI apps, and it also overlaps with developer tools. The category lists 18 verified tools on this site.
The publisher is Comet ML Inc., based in United States. The service launched in 2024.
Who is it for?
It is mostly useful to these profiles: developers, data analysts, and researchers. The need it covers is simple to state: evaluate, monitor and debug AI apps.
Opik is a good candidate if:
- you want to try before paying
- you plan to connect it to your tools or automations through its API
- you want to read the code or host it yourself
Before deciding, run a trial on a real task and measure the time saved: it is the only criterion that really counts.
How much does Opik cost?
Pricing model: open source (public code). A free plan is offered, usually limited in volume or features.
The first paid plan costs $19 per month (Pro Cloud: 100,000 spans per month, up to 50 members and 60-day data retention), according to the pricing page, checked on October 24, 2026.
Per month, that is cheaper than the category median ($49 per month, based on tools with a published price).
To estimate what the same work would cost done directly with an AI model, use our API price calculator. Prices change often: always check the official site before subscribing.
Data and privacy
According to its privacy policy, data is processed in several regions depending on the plan.
Exporting your content: Extraction des traces et des spans par SDK ou API REST. Being able to get your data back makes switching tools easier later.
Three habits apply to every AI tool:
- turn off the use of your content for training if the option exists
- use a work account separate from your personal account
- review everything the tool produces before publishing or sending it
Platforms, languages and API
Opik runs on: web browser and API.
Interface languages are not specified.
A public API lets you call it from your own programs or an automation tool, and plug it into an AI agent.
The source code is public: comet-mlcomet-ml/opik.
How we scored it
Our 83/100 score does not judge output quality: it measures what can be publicly verified about access to the tool, its openness and how far the publisher can be trusted.
| Criterion | Points | What counts |
|---|---|---|
| Access | 25/30 | free tier, published price, French interface |
| Openness | 30/30 | API, data export, open code |
| Trust | 28/40 | identified publisher, declared hosting, age, presence in reference lists |
The full calculation is explained on our method page.
Comparison with alternatives
Opik against other tools in the lLMOps and observability category:
| Tool | Free | Entry price | API | Score |
|---|---|---|---|---|
| Opik | Yes | $19 per month | Yes | 83 |
| Langfuse | Yes | $29 per month | Yes | 95 |
| LangSmith | Yes | $39 per month | Yes | 85 |
| Arize Phoenix | Yes | not published | Yes | 81 |
| Overmind | Yes | $120 per month | Yes | 78 |
| MLflow | Yes | not published | Yes | 78 |
| Respan | Yes | $199 per month | Yes | 71 |
| Prisma AIRS AI Gateway — Portkey | Yes | $49 per month | Yes | 71 |
Verdict
Opik is among the most accessible and transparent tools in its category.
Strengths
- Free tier to try it
- Cheaper than its category median
- Public API
- Public source code
Alternatives
Categories and jobs
Learn more
Frequently asked questions
Is Opik free?
Yes, a free plan exists, with usage limits. The first paid plan costs $19 per month.
Where is Opik data stored?
According to the publisher, in several regions depending on the plan.
Does Opik have an API?
Yes, a public API is documented.
What are the alternatives to Opik?
In the same category: Langfuse, LangSmith, Arize Phoenix, and Overmind.
Opik or Langfuse: which one to choose?
Opik starts at $19 per month, Langfuse at $29 per month and our score is 83/100 for Opik and 95/100 for Langfuse. Try both on the same task before paying.
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Neutrality. No affiliate links. No vendor pays to be reviewed, rated or ranked. Reviews are directed by François Chollet, neutral and factual, and every data point is dated and sourced. How we score