Company lists · Data refreshed September 2026
Top 25 Machine learning training data companies based in the United States
RevenueBase identified 129 machine learning training data companies headquartered in the United States as of September 2026 and tracks 37,317 professional contacts across them, including 3,021 with verified work emails and 1,614 with mobile numbers. San Francisco is the largest hub.
This list covers machine learning training data companies headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest machine learning training data companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | APPENStrong evidence | 19,890 | |||
“Appen has been a leader in AI training data for over 25 years, providing high-quality, diverse datasets that power the world's leading AI models.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 6,538 | ||||
“iMerit is a leader in expert data solutions for training, tuning and evaluating AI models and computer vision systems.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | ObjectwaysPartial evidence | 1,272 | |||
“Objectways is an AI data solutions company trusted by Fortune 500 enterprises and high-growth AI teams worldwide.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | 977 | ||||
“provides ML data operations support with Human-in-the-loop for LLMs and autonomous systems, focusing on AI/ML model training and annotation services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | 899 | ||||
“With 30+ years of experience in data annotation, we support AI innovators to build smarter AI.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 770 | ||||
“Thoth AI is a global AI data solutions company with R&D operations in Silicon Valley, working with AI teams to support the design, development, and deployment of production-grade…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | 751 | ||||
“Cogito Tech is a global managed service provider specializing in scalable data development tailored for AI model development.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | Productive PlayhouseIndirect evidence | 654 | |||
“Productive Playhouse is the execution partner technical program managers trust when scale, compliance, and quality can’t slip.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | pareto.aiStrong evidence | 526 | |||
“Pareto.AI is a talent-first human data collection platform for AI research, empowering the top 0.01% of expert labelers to deliver the highest-quality training data.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | 401 | ||||
“Build Super Accurate AI with us.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 11 | 356 | ||||
“SuperAnnotate bridges the gap between cutting-edge AI innovation and the high-quality human data that powers it - helping advanced AI teams build more intelligent models.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | 331 | ||||
“DataForce delivers high-quality, multimodal training data and services to power the next generation of AI.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | 328 | ||||
“Shaip, by Ubiquity, provides end-to-end AI data services-data collection, licensing, validation, transcription, and annotation-across text, audio, image, and video.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | 231 | ||||
“Abaka AI delivers human intelligence data for frontier AI, helping power advanced systems through a trustworthy data platform.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | 205 | ||||
“Defined.ai is the leading provider of ethical AI data, offering the world’s biggest ethical AI data marketplace alongside subscriptions for flexible data access and custom…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | Label Your DataPartial evidence | 148 | |||
“Label Your Data is a data annotation & labeling company.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | 144 | ||||
“Wow AI | Powered by AIxBlock - is an.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | Liberty Source PBCStrong evidence | 116 | |||
“Liberty Source PBC is a U.S-based provider of human-in-the-loop data services that help companies realize maximum value from their Artificial Intelligence, Machine Learning, and…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | 107 | ||||
“Roboflow creates software-as-a-service products to make building with computer vision easy.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | Opentrain AIPartial evidence | 104 | |||
“The AI Data Labeling Marketplace: Find, hire, and securely pay vetted AI Trainers/data labelers across 110+ countries & any domain expertise.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 78 | ||||
“HumanSignal enables data science teams to build AI models with their company DNA.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 22 | 76 | ||||
“AI Workspace has bagged a unique position in deliberating Sourcing, Data Annotation, and Generative AI services thereby initializing supervised learning for Machine Learning…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 23 | 74 | ||||
“Anolytics is a leading provider of AI data solutions, with offices in India and the USA.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 24 | 59 | ||||
“Centaur.ai data empowers you to build and deploy high-stakes AI.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 25 | Keymakr Data LabelingPartial evidence | 54 | |||
“At Keymakr, we provide exceptional image and video data annotation, data creation, data collection, and data validation services for AI/ML computer vision projects of all sizes.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
Showing 25 of 129 machine learning training data companies based in the United States
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Machine learning training data companies based in the United States at a glance
As of Sep 5, 2026Companies by employee count
Verified emails by last verification
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among machine learning training data companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “machine learning training data companies”. Matching reads each company's description, not its industry code or its name.
- What we exclude
- Companies whose own description does not clearly place them among machine learning training data companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 3,021 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Frequently asked
How many machine learning training data companies are there based in the United States?
RevenueBase identified 129 machine learning training data companies headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
APPEN, headquartered in Kirkland, tops this list with the largest team on record.
Which city has the most machine learning training data companies?
San Francisco leads with 22 headquartered companies, followed by New York (10) and San Jose (8).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 3,021 verified decision-maker contacts tracked across these 129 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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