Company lists · Data refreshed September 2026
Top 25 Ml training data companies worldwide
RevenueBase identified 126 ml training data companies worldwide as of September 2026 and tracks 23,263 professional contacts across them, including 878 with verified work emails. The United States is the largest market and San Francisco the largest hub.
This list covers ml training data companies worldwide, 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. Country and city lists for ml training data companies follow the table.
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 25 largest ml training data companies worldwide
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 | 732 contacts → | ||||
Partial evidence “Toloka is the global leader in human-powered data solutions for AI development.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 4 | 455 contacts → | ||||
Strong evidence “LXT is an emerging leader in AI training data to power intelligent technology for global organizations.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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. | |||||
| 6 | 72 contacts → | ||||
Strong evidence “Globose Technology Solutions is an AI based data collection and data annotation company specialising in providing high quality training data for machine learning and artificial…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 7 | 34 contacts → | ||||
Strong evidence “Are you struggling to find high-quality real-world unbiased training data for your machine-learning algorithms?” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 8 | 31 contacts → | ||||
Partial evidence “Skyfall AI specializes in gathering and curating large volumes of data to create High-Quality Datasets used to train Artificial Intelligence Models.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 9 | 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. | |||||
| 10 | 28 contacts → | ||||
Strong evidence “Unidata is a full-stack data provider for global AI/ML teams.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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. | |||||
| 12 | 25 contacts → | ||||
Strong evidence “Lightly is a data-centric AI company helping ML teams build better computer vision systems, from data curation and labeling to model pretraining and fine-tuning.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 13 | 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. | |||||
| 14 | 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. | |||||
| 15 | 15 contacts → | ||||
Indirect evidence “AI Verse is a French deeptech company (launched in INRIA, a NATO DIANA company) that generates annotated synthetic imagery to train computer vision AI models.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 16 | 13 contacts → | ||||
Partial evidence “APTO is a Japan-based AI data company supporting the development of high-performance AI through high-quality data collection, creation, annotation, and evaluation.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 17 | 12 contacts → | ||||
Partial evidence “Innovatiana turns raw data into AI-ready fuel.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 18 | 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. | |||||
| 19 | 8 contacts → | ||||
Partial evidence “Legally clean datasets for AI training.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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. | |||||
| 21 | 4 contacts → | ||||
Partial evidence “Silera is a data engine for computer vision.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 22 | 3 contacts → | ||||
Strong evidence “At simmetry.ai, we provide high-quality, annotated training data for your machine learning applications.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 23 | 3 contacts → | ||||
Partial evidence “Rexys specializes in providing innovative solutions that enable the generation of synthetic datasets for training and validating artificial intelligence in the field of computer…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 24 | 2 contacts → | ||||
Indirect evidence “We deliver teams building and using computer vision systems with the right datasets to train AI models, while minimizing effort.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 25 | 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. | |||||
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 25 of 126 ml training data companies worldwide
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Ml training data companies worldwide at a glance
As of Sep 28, 2026Companies by employee count
Email recency is reported on each country list linked below.
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.
- Coverage
- Every country. Country and city lists for ml training data companies are linked below.
- What qualifies
- Companies worldwide 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.
- 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, 878 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.
Ml training data companies by location
1 lists · largest firstEvery Ml training data companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
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 worldwide?
RevenueBase identified 126 ml training data companies worldwide 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 country has the most ml training data companies?
The United States leads with 40 companies. Every ml training data companies list by country and city is linked on this page.
Which city has the most ml training data companies?
San Francisco leads with 11 headquartered companies, followed by Bhiwadi (3) and Los Angeles (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 878 verified decision-maker contacts tracked across these 126 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.