LLMOps and observability
Weights & Biases: review, pricing, data and alternatives
Weights & Biases helps people track experiments and applications using models. It compares models and configurations, examines application traces, evaluates agent responses, and manages dataset and model versions. A free tier exists; the first paid plan costs $60 per month. Access and transparency score: 58/100, #13 of 18 in its category.
What is Weights & Biases?
Weights & Biases helps people track experiments and applications using models. It compares models and configurations, examines application traces, evaluates agent responses, and manages dataset and model versions.
According to its documentation, Weights & Biases lets you:
- track experiment parameters and results
- compare multiple models or configurations
- examine traces of applications using models
- evaluate agent responses
- manage dataset and model versions
We file it under LLMOps and observability, the category of tools to evaluate, monitor and debug AI apps, and it also overlaps with data science and machine learning. The category lists 18 verified tools on this site.
The publisher is CoreWeave, Inc., based in United States.
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.
Weights & Biases 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 also work from your phone
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 Weights & Biases cost?
Pricing model: freemium (limited free use, then paid). A free plan is offered, usually limited in volume or features.
The first paid plan costs $60 per month (CoreWeave Forge Pro, billed monthly; Weights & Biases remains available within Forge), according to the pricing page, checked on October 24, 2026.
Per month, that is more expensive 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
The publisher does not clearly state where data is hosted. Assume your content may leave your region.
For professional use, check that a data processing agreement (DPA) is offered, and do not send customers' personal data or confidential documents without one.
Exporting your content: yes (details on the official site). 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
Weights & Biases runs on: web browser, iPhone and iPad, and API.
Interface languages: English, German, Japanese, and Korean.
A public API lets you call it from your own programs or an automation tool, and plug it into an AI agent.
How we scored it
Our 58/100 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 | 20/30 | API, data export, open code |
| Trust | 13/40 | identified publisher, declared hosting, age, presence in reference lists |
The full calculation is explained on our method page.
Comparison with alternatives
Weights & Biases against other tools in the lLMOps and observability category:
Verdict
Weights & Biases is a decent option; compare its price and terms with the category leaders.
Strengths
- Free tier to try it
- Public API
Limitations
- More expensive than its category median
- Data hosting not disclosed
Avoid if…
- You handle sensitive personal data without a processing agreement
Alternatives
Categories and jobs
Learn more
Frequently asked questions
Is Weights & Biases free?
Yes, a free plan exists, with usage limits. The first paid plan costs $60 per month.
Where is Weights & Biases data stored?
The publisher does not clearly say so in its public documentation.
Does Weights & Biases have an API?
Yes, a public API is documented.
What are the alternatives to Weights & Biases?
In the same category: Langfuse, LangSmith, Opik, and Arize Phoenix.
Weights & Biases or Langfuse: which one to choose?
Weights & Biases starts at $60 per month, Langfuse at $29 per month and our score is 58/100 for Weights & Biases 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