Amazon is closing the MTurk front door

Amazon’s small Mechanical Turk notice is a useful morning signal: AI still needs human feedback, but the old open microtask market is no longer the clean answer.

What changed. Amazon’s Mechanical Turk homepage now says MTurk will be closed to new customers effective July 30, 2026. Existing users “will not be impacted.” The linked AWS maintenance page defines maintenance-stage services as ones where customers cannot onboard, existing customers can continue, AWS keeps operating and supporting them, and no new functionality is planned. This is not a shutdown notice. It is a front-door closure.

Why it matters. MTurk mattered to AI because it made human labor feel like an API. Amazon’s page describes it as a global, on-demand workforce for data validation, content moderation, research, and machine-learning development. The SageMaker documentation explains that the public MTurk workforce can be used inside Ground Truth labeling jobs and Amazon A2I human-review workflows, with the important caveat that customers should not send confidential information, personal information, or protected health information to that public workforce. That caveat is the whole story in miniature: the more valuable and sensitive AI feedback becomes, the less attractive a broad public crowd becomes as the default wrapper.

The adjacent change is A2I. Amazon’s A2I docs now carry their own note: AWS will close new customer access to Amazon Augmented AI on July 30, while existing customers can continue and AWS will keep investing in security and availability, not new features. A2I was the productized version of a common machine-learning pattern: send low-confidence predictions or random samples to human reviewers, then use the results to check or improve the system. Putting that workflow into maintenance does not mean human review is over. It means the old managed service shape is being frozen.

The deeper problem was already visible. In 2023, Veniamin Veselovsky, Manoel Horta Ribeiro, and Robert West reran an MTurk abstract-summarization task and estimated that 33–46% of the crowd-worker summaries were produced with help from LLMs. They were careful about the limit: this was one text-production task, not every kind of work. But it captured the fault line. If you hire humans to produce a human gold standard, and some of the “human” outputs are model outputs routed through workers, the value of the market changes. The worker may still matter, but increasingly as a filter, auditor, domain judge, or accountable operator rather than as an anonymous source of de novo text.

The read. The MTurk notice is not “AI replaces all humans.” It is closer to the opposite. The AI stack still needs human judgment for evaluation, feedback, exceptions, safety, preference data, domain tuning, and accountability. But the wrapper is moving away from open public microtasks and toward narrower, auditable, domain-specific workflows: private teams, vetted vendors, managed evaluation programs, or product-specific feedback loops.

What to watch next is whether AWS names a preferred replacement path for new customers who would have used MTurk or A2I, and whether other cloud platforms make the same move: less public crowd, more controlled review.

Source graph: Semble source collection