Amazon Mechanical Turk (MTurk) was a crowdsourcing website with which businesses could hire remotely located "crowdworkers" to perform discrete on-demand tasks that computers are currently unable to do as economically. It was operated under Amazon Web Services, and was owned by Amazon. Employers, known as requesters, posted jobs known as Human Intelligence Tasks (HITs), such as identifying specific content in an image or video, writing product descriptions, or answering survey questions. Workers, colloquially known as Turkers or crowdworkers, browsed among existing jobs and completed them in exchange for a fee set by the requester. To place jobs, requesters used an open application programming interface (API), or the more limited MTurk Requester site. , requesters could register from 49 approved countries. It was named after the Mechanical Turk, a chess machine.
Amazon closed the service on September 30, 2026 after announcing the intention to do so in August 2026. Users are given until October 30, 2026 to finalize their transactions.
History The service was conceived by Venky Harinarayan in a U.S. patent disclosure in 2001. Amazon coined the term artificial artificial intelligence for processes that outsource some parts of a computer program to humans, for those tasks carried out much faster by humans than computers. MTurk product director Peter Cohen identified Jeff Bezos as the person who first proposed the concept.
The name Mechanical Turk was inspired by an 18th-century chess-playing automaton of the same name, often simply nicknamed as "The Turk". Made by Hungarian author and engineer Wolfgang von Kempelen, the machine became an international spectacle, touring Europe, and beating both Napoleon Bonaparte and Benjamin Franklin. It was later revealed that this "machine" was not an automaton, but rather controlled by a human chess master hidden in the cabinet beneath the board, puppeting the movements of a humanoid dummy. Analogously, the Mechanical Turk online service uses remote human labor hidden behind a computer interface to help employers perform tasks that are not currently possible using a true machine.
MTurk was launched in 2005. In March 2007, there were reportedly more than 100,000 workers in over 100 countries. This increased to over 500,000 registered workers from over 190 countries in January 2011. That year, Techlist published an interactive map pinpointing the locations of 50,000 of their MTurk workers around the world. By 2018, research demonstrated that while over 100,000 workers were available on the platform at any time, only around 2,000 were actively working.
Closure On July 5, 2026, Amazon announced that Mechanical Turk would stop accepting new customers on July 30, and that Amazon Web Services would maintain the service's security and availability for existing customers but add no new features. On August 25, Amazon announced that it would close the service entirely on September 30, 2026, in a notice posted to the Mechanical Turk website citing an assessment of the company's "programs, tools and services". Analysts attributed the decision behind the closure to mechanical turk workers moving to other data-labeling competitors such as Scale AI and Mercor.
Overview A user of Mechanical Turk could be either a "Worker" (contractor) or a "Requester" (employer). Workers had access to a dashboard that displays three sections: total earnings, HIT status, and HIT totals. Workers set their own hours and were not under any obligation to accept any particular task.
Amazon classifies Workers as contractors rather than employees and does not pay payroll taxes. Classifying Workers as contractors allows Amazon to avoid things like minimum wage, overtime, and workers compensation—this was a common practice among "gig economy" platforms. In the United States, where a supermajority of MTurk workers are located, workers are legally required to report their income as self-employment income. The differing legality of this arrangement in countries with stronger labour laws made the actual international accessibility of the program uncertain.
In 2013, the average wage for the multiple microtasks assigned, if performed quickly, was about one dollar an hour, with each task averaging a few cents."Amazon Mechanical Turk: The Digital Sweatshop" Ellen Cushing Utne Reader January–February 2013 However, calculating people's average hourly earnings on a microtask site was extremely difficult, and several sources of data show average hourly earnings in the $5–$9 per hour range among a substantial number of Workers, while the most experienced, active, and proficient workers may earn over $20 per hour.
Workers could have a postal address anywhere in the world. Payment for completing tasks could be redeemed on Amazon.com via gift certificate (gift certificates were the only payment option available to international workers, apart from India) or could be transferred to a Worker's U.S. bank account.
Requesters could ask that Workers fulfill qualifications before engaging in a task, and they could establish a test designed to verify the qualification. They could also accept or reject the result sent by the Worker, which affects the Worker's reputation. , Requesters paid Amazon a minimum 20% commission on the price of successfully completed jobs, with increased amounts for . Requesters could use the Amazon Mechanical Turk API to programmatically integrate the results of the work directly into their business processes and systems. When employers set up a job, they had to specify how much they were paying for each HIT accomplished, how many workers they wanted to work on each HIT, the maximum time a worker had to work on a single task, how much time the workers had to complete the work, as well as the specific details about the job they want to be completed.
Location of Turkers Workers were primarily located in the United States since the platform's inception with demographics generally similar to the overall Internet population in the U.S. Within the U.S. workers were fairly evenly spread across states, proportional to each state's share of the U.S. population. , between 15 and 30 thousand people in the U.S. completed at least one HIT each month and about 4,500 new people joined MTurk each month.
Cash payments for Indian workers were introduced in 2010, which updated the demographics of workers, who however remained primarily within the United States. A website showing worker demographics in May 2015 showed that 80% of workers were located in the United States, with the remaining 20% located elsewhere in the world, most of whom were in India. In May 2019, approximately 60% were in the U.S., 40% elsewhere (approximately 30% in India). In early 2023 about 90% of workers were from the U.S. and about half of the remainder from India.
Uses Human-subject research , numerous researchers have explored the viability of Mechanical Turk to recruit subjects for social science experiments. Researchers have generally found that while samples of respondents obtained through Mechanical Turk did not perfectly match all relevant characteristics of the U.S. population, they were also not wildly misrepresentative. As a result, thousands of papers that relied on data collected from Mechanical Turk workers were published each year, including hundreds in top ranked academic journals.
A challenge with using MTurk for human-subject research had been maintaining data quality. A study published in 2021 found that the types of quality control approaches used by researchers (such as checking for bots, VPN users, or workers willing to submit dishonest responses) could meaningfully influence survey results. They demonstrated this via impact on three common behavioral/mental healthcare screening tools. Even though managing data quality requires work from researchers, there is a large body of research showing how to gather high quality data from MTurk. The cost of using MTurk was considerably lower than many other means of conducting surveys, so many researchers continued to use it.
The general consensus among researchers was that the service works best for recruiting a diverse sample; it was less successful with studies that required more precisely defined populations or that require a representative sample of the population as a whole. Many papers have been published on the demographics of the MTurk population. MTurk workers tend to be younger, more educated, more liberal, and slightly less wealthy than the U.S. population overall.
Machine Learning Supervised Machine Learning algorithms require large amounts of human-annotated data to be trained successfully. Machine learning researchers have hired Workers through Mechanical Turk to produce datasets such as SQuAD, a question answering dataset.
Missing persons searches , the service has been used to search for prominent missing individuals. This use was first suggested during the search for James Kim, but his body was found before any technical progress was made. That summer, computer scientist Jim Gray disappeared on his yacht and Amazon's Werner Vogels, a personal friend, made arrangements for DigitalGlobe, which provides satellite data for Google Maps and Google Earth, to put recent photography of the Farallon Islands on Mechanical Turk. A front-page story on Digg attracted 12,000 searchers who worked with imaging professionals on the same data. The search was unsuccessful.
In September 2007, a similar arrangement was repeated in the search for aviator Steve Fossett. Satellite data was divided into sections, and Mechanical Turk users were asked to flag images with "foreign objects" that might be a crash site or other evidence that should be examined more closely. This search was also unsuccessful. The satellite imagery was mostly within a 50-mile radius, but the crash site was eventually found by hikers about a year later, 65 miles away.
Artistic works MTurk has also been used as a tool for artistic creation. One of the first artists to work with Mechanical Turk was xtine burrough, with The Mechanical Olympics (2008), Endless Om (2015), and Mediations on Digital Labor (2015).Project: http://www.missconceptions.net/mediations/ Another work was artist Aaron Koblin's Ten Thousand Cents (2008).
Third-party programming Programmers have developed browser extensions and scripts designed to simplify the process of completing jobs. Amazon has stated that they disapprove of scripts that completely automate the process and preclude the human element. This was because of the concern that the task completion process—e.g. answering a survey—could be gamed with random responses, and the resultant collected data could be worthless. Accounts using so-called automated bots have been banned.
API Amazon makes available an application programming interface (API) for the MTurk system. The MTurk API let a programmer submit jobs, retrieve completed work, and approve or reject that work. In 2017, Amazon launched support for AWS Software Development Kits (SDK), allowing for nine new SDKs available to MTurk Users. MTurk was accessible via API from the following languages: Python, JavaScript, Java, .NET, Go, Ruby, PHP, or C++. Web sites and web services could use the API to integrate MTurk work into other web applications, providing users with alternatives to the interface Amazon has built for these functions.
Use case examples
Processing photos / videos Amazon Mechanical Turk provides a platform for processing images, a task well-suited to human intelligence. Requesters have created tasks that ask workers to label objects found in an image, select the most relevant picture in a group of pictures, screen inappropriate content, classify objects in satellite images, or digitize text from images such as scanned forms filled out by hand.
Data cleaning / verification