Company lists · Data refreshed September 2026

Top 25 Annotation services for machine learning worldwide

RevenueBase identified 514 company matches for annotation services for machine learning worldwide as of September 2026 and tracks 17,228 professional contacts across them, including 1,440 with verified work emails. India is the largest market and Bengaluru the largest hub.

This list covers company matches for annotation services for machine learning worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 27, 2026. Country and city lists for annotation services for machine learning follow the table.

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.

How to read this list RevenueBase SmartSearch · Exact Recorded Sep 27, 2026 How this list was built
514Companies
17,228Contacts tracked
1,440Verified emails
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The 25 largest annotation services for machine learning worldwide

Ranked by team size
Top 25 of 514 company matches for annotation services for machine learning worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 27, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchScottsdale, AZ, United StatesHQ recorded Sep 27, 20261,001-5,0001,272 contacts →

Exact match

“Objectways is an AI data solutions company trusted by Fortune 500 enterprises and high-growth AI teams worldwide.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
2Exact matchNew York, NY, United StatesHQ recorded Sep 27, 20261,001-5,000977 contacts →

Exact match

“provides ML data operations support with Human-in-the-loop for LLMs and autonomous systems, focusing on AI/ML model training and annotation services.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
3Exact matchMiami, FL, United StatesHQ recorded Sep 27, 2026501-1,000899 contacts →

Exact match

“With 30+ years of experience in data annotation, we support AI innovators to build smarter AI.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
4Exact matchAmsterdam, NetherlandsHQ recorded Sep 27, 2026n/a732 contacts →

Exact match

“Toloka is the global leader in human-powered data solutions for AI development.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
5Exact matchLos Angeles, CA, United StatesHQ recorded Sep 27, 2026201-500654 contacts →

Exact match

“Productive Playhouse is the execution partner technical program managers trust when scale, compliance, and quality can’t slip.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
6Exact matchCyprusHQ recorded Sep 27, 20261,001-5,000567 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
7Exact matchStanford, CA, United StatesHQ recorded Sep 27, 202651-200526 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
8Exact matchUnited StatesHQ recorded Sep 27, 20261,001-5,000524 contacts →

Exact match

“With 27+ years of experience, Welo Data is the human-centered infrastructure for globally effective AI.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
9Exact matchCastlebar, IrelandHQ recorded Sep 27, 2026n/a493 contacts →

Exact match

“Peroptyx is a provider of location-based machine learning (ML) training data and model evaluation solutions to global consumer technology brands.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
10Exact matchMississauga, ON, CanadaHQ recorded Sep 27, 2026501-1,000455 contacts →

Exact match

“LXT is an emerging leader in AI training data to power intelligent technology for global organizations.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
11Exact matchPune, IndiaHQ recorded Sep 27, 2026201-500437 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
12Exact matchSan Francisco, CA, United StatesHQ recorded Sep 27, 202651-200356 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
13Exact matchNew York, NY, United StatesHQ recorded Sep 27, 2026201-500328 contacts →

Exact match

“Shaip, by Ubiquity, provides end-to-end AI data services-data collection, licensing, validation, transcription, and annotation-across text, audio, image, and video.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
14Exact matchToronto, ON, CanadaHQ recorded Sep 27, 202651-200242 contacts →

Exact match

“At Quantigo AI, we empower businesses with cutting-edge AI training data solutions.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
15Exact matchSan Jose, United StatesHQ recorded Sep 27, 20261,001-5,000208 contacts →

Exact match

“Lifewood Data Technology is a global AI data services company headquartered in Hong Kong.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
16Exact matchKuala Lumpur, MalaysiaHQ recorded Sep 27, 2026n/a181 contacts →

Exact match

“Supahands provides fully managed data labelling services for machine learning.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
17Exact matchBangalore, IndiaHQ recorded Sep 27, 202651-200160 contacts →

Exact match

“Welcome to TAGFact, your premier media intelligence and data annotation/labeling solution.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
18Exact matchWilmington, DE, United StatesHQ recorded Sep 27, 2026201-500148 contacts →

Exact match

“Label Your Data is a data annotation & labeling company.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
19Exact matchNewark, DE, United StatesHQ recorded Sep 27, 2026201-500144 contacts →

Exact match

“Wow AI | Powered by AIxBlock - is an.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
20Exact matchIstanbul, TürkiyeHQ recorded Sep 27, 2026n/a128 contacts →

Exact match

“Prosessor.AI is a high-grade AI/ML data provider company for a smarter world.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
21Exact matchHampton, VA, United StatesHQ recorded Sep 27, 202651-200116 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
22Exact matchRemote, United StatesHQ recorded Sep 27, 202651-200107 contacts →

Exact match

“Roboflow creates software-as-a-service products to make building with computer vision easy.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
23Exact matchBengaluru, IndiaHQ recorded Sep 27, 202651-200107 contacts →

Exact match

“Fueling the AI age.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
24Exact matchAccra, GhanaHQ recorded Sep 27, 202611-50106 contacts →

Exact match

“Data labeling solutions for artificial intelligence learning Computer Vision Natural language treatment Speech recognition”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
25Exact matchLondon, United KingdomHQ recorded Sep 27, 202651-200104 contacts →

Exact match

“DataEQ uses a Crowd of humans to label millions of unstructured data points.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase

Showing 25 of 514 annotation services for machine learning worldwide

See the full list, filter by size, metro and specialty, and access 1,440 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Annotation services for machine learning worldwide at a glance

As of Sep 27, 2026
8.4%Verified-email coverage
33.5Average contacts per company
11-50Median size (employees)
2.9%Largest-city concentration · Bengaluru
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
155
11-50
177
51-200
120
201-500
37
501-1,000
12
1,001-5,000
10
5,001-10,000
3

Email recency is reported on each country list linked below.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

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.
Coverage
Every country. Country and city lists for annotation services for machine learning are linked below.
What qualifies
Company records worldwide whose business descriptions match “annotation services for machine learning” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 1,440 professional contacts with verified work emails across the full matched dataset. 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 27, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Annotation services for machine learning by location

2 lists · largest first

Every Annotation services for machine learning 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 SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “annotation services for machine learning”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many annotation services for machine learning are there worldwide?

RevenueBase identified 514 company matches for annotation services for machine learning worldwide as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Objectways tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most annotation services for machine learning?

India leads with 149 companies, followed by the United States (88). Every annotation services for machine learning list by country and city is linked on this page.

Which city has the most annotation services for machine learning?

Bengaluru leads with 15 company records, followed by San Francisco (12) and Kolkata (11).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 1,440 professional contacts with verified work emails tracked across these 514 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 27, 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.