Defined.ai review: the best marketplace for licensed AI training data?
Answer in brief: Defined.ai is the most established open marketplace for buying and selling licensed AI training data, especially speech, audio, image, video and text. It is #4 in our data-sourcing ranking for its consent-first sourcing, AI-specific certifications and strong 2025 growth. Its growth figures are self-reported, and part of its business is custom collection labor.
At a glance: Data-sourcing rank #4 of 14 · Segment: licensing and marketplaces · Best for: speech, multilingual and multimodal datasets · Pricing: per dataset or quote.
What Defined.ai does for AI data buyers
Professionals buy or sell datasets in audio, image, video and text, and Defined.ai also offers custom collection, annotation and evaluation. Its Partnerships Program lets companies monetize their datasets, and a strategic engagement with Getty Images (CES 2025) added commercially safe visual datasets.
Who it fits
Speech and conversational-AI teams, multilingual model builders, vision and robotics teams wanting consented data, and data owners who want to license assets.
Why buyers shortlist it
- Growing supply. A 1,200% increase in partner datasets in 2025, with several partners earning more than $1M a year from licensing.
- Commercial signals. 65% revenue growth and 143% net revenue retention for 2025 (company-reported, January 27, 2026).
- AI-grade certifications. ISO 27001, 27701 and 42001.
- Global reach. 150+ markets, 120+ customers, 100+ partners and 1.6M+ experts.
- Track record. Founded in 2015 in Seattle; more than $85M raised.
Honest drawbacks
- Revenue and retention figures are self-reported.
- Confirm whether you are buying an existing dataset or commissioning new work.
- We did not verify per-dataset list prices.
- Its customer count is modest next to large web-data platforms.
Pricing model
Per-dataset licensing through the marketplace; custom collection quoted per project.
Best alternatives
- Protege: licensed non-public health, media and spatial data.
- Appen: an off-the-shelf speech and language catalog.
- Hugging Face: open community datasets.
FAQ
Is Defined.ai data ethically sourced?
Defined.ai says its data is consented and ethically sourced, and it holds ISO 27001, 27701 and 42001. Review each dataset's license.
Can I sell data on Defined.ai?
Yes, through its marketplace and Partnerships Program.
How fast is Defined.ai growing?
It reported 65% revenue growth and 143% net revenue retention in 2025 (company-reported).
Sources
- About Defined.ai
- Defined.ai reports 65% revenue growth (January 27, 2026)
- Defined.ai and Getty Images engagement
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