Company lists · Data refreshed September 2026
Top 25 AI training data services worldwide
RevenueBase identified 799 AI training data services worldwide as of September 2026 and tracks 53,547 professional contacts across them, including 3,734 with verified work emails. India is the largest market and San Francisco the largest hub.
This list covers AI training data services 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 21, 2026. Country and city lists for AI training data services 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 AI training data services 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 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 6,538 contacts → | ||||
Strong evidence “iMerit is a leader in expert data solutions for training, tuning and evaluating AI models and computer vision systems.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 3,009 contacts → | ||||
Partial evidence “What Does Sama Do Sama gets your AI project to production-and helps you stay there.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 1,272 contacts → | ||||
Strong evidence “Objectways is an AI data solutions company trusted by Fortune 500 enterprises and high-growth AI teams worldwide.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 977 contacts → | ||||
Strong evidence “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: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 899 contacts → | ||||
Strong evidence “With 30+ years of experience in data annotation, we support AI innovators to build smarter AI.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 770 contacts → | ||||
Strong 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 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 751 contacts → | ||||
Strong evidence “Cogito Tech is a global managed service provider specializing in scalable data development tailored for AI model development.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 732 contacts → | ||||
Strong evidence “Toloka is the global leader in human-powered data solutions for AI development.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 654 contacts → | ||||
Indirect evidence “Productive Playhouse is the execution partner technical program managers trust when scale, compliance, and quality can’t slip.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 567 contacts → | ||||
Strong evidence “Mindy Support delivers end-to-end AI data infrastructure - from data collection and annotation to LLM training and BPO - trusted by Fortune 500 and GAFAM companies.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 551 contacts → | ||||
Strong evidence “We leverage our AI data and localization experience – gained from working with the largest AI/NLP deployments in the world – to help train and fine-tune AI and LLM apps.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 526 contacts → | ||||
Strong evidence “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: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 524 contacts → | ||||
Strong evidence “With 27+ years of experience, Welo Data is the human-centered infrastructure for globally effective AI.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 493 contacts → | ||||
Strong evidence “Peroptyx is a provider of location-based machine learning (ML) training data and model evaluation solutions to global consumer technology brands.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 437 contacts → | ||||
Partial evidence “Dedicated to revolutionizing the way outsourcing industries operate, Qualitas Global Services has emerged as a trusted business partner & key player in the data services industry.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 401 contacts → | ||||
Partial evidence “Build Super Accurate AI with us.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 374 contacts → | ||||
Strong evidence “Revelo provides data infrastructure for frontier model AI code generation, including expert annotators, eval frameworks, and reinforcement learning gyms.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 356 contacts → | ||||
Strong evidence “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: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 331 contacts → | ||||
Strong evidence “DataForce delivers high-quality, multimodal training data and services to power the next generation of AI.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 328 contacts → | ||||
Strong evidence “Shaip, by Ubiquity, provides end-to-end AI data services-data collection, licensing, validation, transcription, and annotation-across text, audio, image, and video.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 242 contacts → | ||||
Strong evidence “At Quantigo AI, we empower businesses with cutting-edge AI training data solutions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 231 contacts → | ||||
Strong evidence “Abaka AI delivers human intelligence data for frontier AI, helping power advanced systems through a trustworthy data platform.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 208 contacts → | ||||
Strong evidence “Lifewood Data Technology is a global AI data services company headquartered in Hong Kong.” Source: RevenueBase Database · checked Sep 21, 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: AI training data services. 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 AI training data services.
- Partial evidence
- Its own public description names part of AI training data services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name AI training data services. 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 799 AI training data services worldwide
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AI training data services worldwide at a glance
As of Sep 21, 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 AI training data services, 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 AI training data services are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “AI training data services”. 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 AI training data services), 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 AI training data services, 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, 3,734 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 21, 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.
AI training data services by location
2 lists · largest firstEvery AI training data services 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 AI training data services, 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 AI training data services are there worldwide?
RevenueBase identified 799 AI training data services 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 AI training data services?
India leads with 184 companies, followed by the United States (154). Every AI training data services list by country and city is linked on this page.
Which city has the most AI training data services?
San Francisco leads with 23 headquartered companies, followed by Bengaluru (15) and London (14).
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 3,734 verified decision-maker contacts tracked across these 799 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 21, 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.