How big is the AI training data market?

Market size figures for AI training data appear in pitch decks, press releases and news stories, often without the firm or year that produced them. They are estimates from commercial research firms, and they disagree by a factor of nearly three for the same year.

This guide compares the published estimates, explains why they differ and sets them beside harder numbers from US company filings and the reported deal values in our AI data deals tracker.

How big is the AI training data market?

The AI training data market was worth between $3.2 billion and $8.74 billion in 2025, according to the research firms that publish estimates. Each figure below is the firm's own estimate, taken from its report page or press release in November 2026.

Why do AI training data market estimates differ?

AI training data market estimates differ because each firm draws the market boundary in a different place, starts from a different base year and uses its own unpublished model. Small differences in definition become large differences in a forecast compounded over six to nine years.

Mordor Intelligence's definition includes custom dataset creation, which it projects as the fastest-growing offering at 33.74% a year through 2031. A firm that counts the services work of building datasets will report a larger market than one that counts dataset products alone.

Method matters too. Grand View Research says its findings rest on proprietary technology databases, executive interviews and regulatory analysis, with internal peer review. None of the public summaries we read lists the company revenues or licensing deals included, so you cannot reconcile one firm's number with another's.

What do US company filings show about data licensing revenue?

US company filings give audited or sworn figures for individual sellers, which are narrower than market estimates but more reliable. Two filings stand out.

Reddit's S-1 also describes how the money is earned: customers receive the right to access data over the contract period, the price is generally a fixed fee or usage-based fee and revenue is recognized over the license period. It warns that substantially all of the contract value came from one partner at the time of filing.

Shutterstock's 10-K figure includes Giphy and Shutterstock Studios as well as data licensing, so it is not a pure AI data number. Scale AI's valuation reflects what investors pay for a training-data company, not the size of the market it serves.

Reported AI data deals show a market with a few very large publisher and platform licenses and a long tail of small company sales. The table lists every deal in our tracker with a reported value, exactly as the cited source reported it.

The largest reported value is News Corp's license to OpenAI, at about $250 million over five years in cash and credits according to The Wall Street Journal. At the other end, MIT Technology Review reported about $25,000 for the codebase of a shut-down crypto startup in October 2026.

Many deals never publish a price. Of the 21 deals in our tracker, 11 are listed as undisclosed, including OpenAI's licenses with the Financial Times, Condé Nast and Stack Overflow. Adding up reported values would understate the market, so we do not publish a total.

Do market estimates include payments to data owners?

It is not clear whether published market estimates include licensing payments to data owners such as publishers, platforms and companies. The firms' public summaries do not say which payments they count.

Mordor Intelligence's report cites the New York Times licensing agreement with Amazon in May 2025 as an example of rights-cleared content in the custom dataset segment, which suggests it considers such licenses part of the picture. Whether their value is in the $8.74 billion figure is not stated. If your question is what AI companies pay data owners, filings and deal reports answer it better than market sizing does.

Which market size figure should you use?

Use the range rather than one firm's number, and name each source with its year. For a single figure, pick the firm whose definition matches your question, such as Mordor Intelligence if you include custom dataset creation services.

• For a pitch or report: quote the range of 2025 estimates, $3.2 billion to $8.74 billion, with both firms named
• For a forecast: show at least two forecasts with their horizons, since 2029, 2031, 2033 and 2035 are not comparable
• For pricing a deal: ignore market size and use published price ranges and comparable deals
• For a seller's valuation: use buyer offers and deal values in your data type, not a share of the market

For prices, our AI data price index compiles published payout ranges and reported deal values in one table, and our guide to AI training data pricing models explains how deals are structured.

What does market growth mean for AI data buyers?

Market growth means more competition for scarce, rights-cleared data, especially proprietary company records and expert work. In the 2026 auction for bankrupt Spirit Airlines' de-identified business data, Google's reported $10 million bid won, micro1 filed a competing bid and Mercor was named as alternate bidder. Court approval was pending at the time of reporting.

For buyers, that argues for starting procurement early and paying attention to exclusivity. Our guide to running an AI training data procurement sets out the process, and our guide to synthetic vs licensed training data covers when real data is worth the cost.

How does Sell My Data To AI fit into this market?

Sell My Data To AI is an independent broker between data owners and AI teams. We do not own an AI model and we do not buy data for our own use. Buyers pay nothing to submit a requirement or review a shortlist, and sellers pay nothing to be assessed. To source data, submit a data requirement. To license your own records, start with a data valuation.