Defined.ai review: the best place to license ready-made AI training data?

Answer in brief: Defined.ai is our top pick for the license route. Its marketplace sells ready-made speech, text, image, video and multimodal datasets. You can download free samples, and its standard license is perpetual and allows commercial use of models trained on the data. It is ISO 27001, 27701 and 42001 certified, and GDPR and HIPAA compliant. Catalog data will not be tailored to your model's specific failures, and it does not offer refunds.

Licensed, compliant data you can buy today. Browse, check a free sample, buy, and receive the data by file transfer or API.

Independent research, checked against Defined.ai's official site and FAQ on 2026-11-09. We have not tested the service.

Where Defined.ai fits in the five routes

License: a marketplace of ready-made datasets across domains such as healthcare, call centers, automotive and STEM, which can be customized by format, sample rate and more. Collect: custom collection of speech, audio, image, video and multimodal data. Label: data annotation with a model in the loop, plus data and model evaluation. We found no synthetic-data offer on its current site.

Who it fits

• Teams that need speech or multilingual data now.
• Regulated buyers who need clear licensing and certified handling.
• Academic teams, which can get significant discounts or free data after due diligence.

Strengths

• Clear license: perpetual, and covers commercial use of models trained on the data.
• Try before you buy: free samples can be downloaded from the site.
• Global crowd: 1.6M+ contributors in 150+ countries, covering 500+ languages, dialects and locales, by its count.
• Fair-pay policy: at least minimum wage, and living wages where required.

Honest drawbacks

• No refunds, so check the sample carefully.
• Catalog data is not built around your model's failures.
• Custom work and volume discounts are quoted, not listed.

Pricing model

Individual dataset licenses, with volume discounts quoted. It accepts USD by ACH bank transfer, and datasets are delivered once funds clear, typically in 2–3 business days. If you need a purchase order, SOW or other paperwork, Defined.ai asks you to talk to its team.

Best alternatives

• Appen: an OTS catalog plus permissioned enterprise data.
• TELUS Digital: an extendable catalog with managed collection.
• Surge AI: frontier off-the-shelf data on pay-if-it-works terms.

For a full comparison of dataset catalogs, see Best AI datasets.

FAQ

What are Defined.ai's license terms?

Its standard license is perpetual and allows the commercialization of models built on the data.

How do I pay Defined.ai?

In USD by ACH bank transfer. For a purchase order or SOW, contact its team.

Can I get a free sample?

Yes. Samples can be downloaded from the website and share the full dataset's structure.

Sources

• defined.ai
• Defined.ai FAQ
• Defined.ai marketplace

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