Company lists · Data refreshed September 2026
Top 12 Ml training data companies based in the United States
RevenueBase identified 40 ml training data companies headquartered in the United States as of September 2026 and tracks 21,564 professional contacts across them, including 699 with verified work emails. San Francisco is the largest hub.
This list covers ml 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 28, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 12 largest ml training data companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 19,890 contacts → | ||||
Strong evidence “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: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 2 | 770 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 3 | 428 contacts → | ||||
Partial evidence “Wirestock powers AI labs with premium data from a global network of creators.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 4 | 30 contacts → | ||||
Strong evidence “Hub provides real-world training data to frontier AI labs and robotics companies.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 5 | 26 contacts → | ||||
Indirect evidence “Anote is an applied AI research company in New York City.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 6 | 21 contacts → | ||||
Indirect evidence “Abundant is an applied research lab building the simulation engine for superintelligence.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 7 | 17 contacts → | ||||
Partial evidence “Reliabl is a Machine Learning training & evaluation platform that helps teams annotate nuanced content together, transforming user insights into high-quality, accurately labeled…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 8 | 10 contacts → | ||||
Indirect evidence “DagsHub allows you to curate and annotate multimodal datasets, track experiments, and manage models on a single platform.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 9 | 8 contacts → | ||||
Partial evidence “Legally clean datasets for AI training.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 10 | 8 contacts → | ||||
Indirect evidence “Generate, annotate, clean and enrich datasets for all your AI needs with Refuel's LLM-powered platform.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 11 | 2 contacts → | ||||
Partial evidence “Edgecase is a data factory for A.I.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 12 | 2 contacts → | ||||
Strong evidence “Join our mission to perfect training data for AI.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: ml training data companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names ml training data companies.
- Partial evidence
- Its own public description names part of ml training data companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name ml training data companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 12 of 40 ml training data companies based in the United States
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Ml training data companies based in the United States at a glance
As of Sep 28, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 40 companies.
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 ml training data companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search 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 Smart Search, 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 “ml training data companies”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names ml training data companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among ml 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 its RevenueBase Smart Search 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, 699 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 28, 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
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names ml training data companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many ml training data companies are there based in the United States?
RevenueBase identified 40 ml 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 ml training data companies?
San Francisco leads with 11 headquartered companies, followed by Los Angeles (3) and San Jose (3).
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 699 verified decision-maker contacts tracked across these 40 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 28, 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 Smart Search, 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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