Amazon is closing Mechanical Turk, the site that fed early AI

Amazon will shut down Mechanical Turk on September 30, closing after 21 years the marketplace that paid humans small sums to do work computers could not yet manage — and, in doing so, helped teach computers to manage it.

The company announced the closure on Tuesday with little ceremony. "We regularly evaluate our programs, tools and services and make adjustments based on those assessments," Amazon said, offering no further explanation. The platform had stopped accepting new customers in July, and the signs of decline were older still: as specialist data-labeling firms such as Scale AI, Mercor and Prolific built businesses recruiting skilled annotators for AI developers, Amazon invested less and less in its aging marketplace.

Launched in 2005 and named after an 18th-century chess-playing "machine" that concealed a human player inside, Mechanical Turk was described by Jeff Bezos as "artificial artificial intelligence": instead of software imitating people, people quietly did the work software could not. Businesses posted microtasks — labeling images, transcribing audio, moderating content, deduplicating records, answering surveys — and a global pool of workers, more than 500,000 across 190 countries at the platform's documented peak, completed them for cents apiece.

That arrangement made the platform one of the quiet foundations of modern machine learning. Academic researchers used it for two decades to run studies and build labeled datasets; AI labs used those datasets to teach models the kinds of judgments that were, as one Allen Institute for AI researcher put it, easy for humans and still quite hard for machines. The machines learned. The irony arrived on schedule: a 2023 Swiss study found that roughly 46 percent of the workers it examined appeared to be using AI models to complete their tasks — the humans hired to stand in for machines had begun delegating to them.

For the workers who relied on it, the closure is a livelihood ending on five weeks' notice, and the announcement is also a data point in a larger shift: the AI economy still buys enormous amounts of human judgment, but it now buys it through curated expert networks rather than an open bulletin board of anonymous microtasks. The site that Bezos pitched as artificial artificial intelligence is closing in the first era when the artificial kind mostly suffices.