What Sigma AI does

Sigma AI is a Madrid-headquartered, private data annotation and data collection company that provides human-in-the-loop training data services for artificial intelligence systems. Founded in 2008 by Daniel Tapias and Nuria Gómez, the company operates a 25,000+ annotator workforce spanning 120 countries and 500–700+ languages and dialects, delivering structured training data across text, audio, image, video, and multimodal inputs. Its offering is organized into six service modules — Sigma Data (sourcing and synthesis), Sigma Integration (multimodal annotation), Sigma Meaning (linguistic annotation), Sigma Truth (ground truth verification), Sigma Protection (security, red teaming, and PII handling), and Sigma Perception (tone, emotion, and intent) — with Sigma Cognition operating as a sister-company AI consultancy.

The company targets enterprise customers building frontier AI systems, with disclosed long-term relationships with 4 of 5 global tech titans and case studies spanning RLHF side-by-side evaluation, voice annotation, multilingual intent labeling, and multimodal localization across 15+ markets. Revenue is generated through quote-based enterprise contracts with hourly and unit-based pricing, supplemented by a $3,000 fixed-fee two-week pilot program introduced in September 2025. Sigma AI holds ISO 27001, SOC 2 Type II, GDPR, CCPA, and HIPAA-equivalent certifications and operates secure annotation facilities designed for confidential data handling.

Sigma AI is privately held under SIGMA Group (US holding entity, Miami). Its first disclosed external funding came in July 2025 from Trading Technologies to build a TT AI and Innovation Hub. Official employee headcount is 251–500, with the broader annotator/labor pool materially larger. The company maintains offices in Madrid, Miami (North American HQ), and London, and reports coverage across five continents.

Name

Sigma AI

Legal name

SIGMA. AI, SLU

Website

https://sigma.ai

Company type

Private

Founded year

2008

Operating status

Operating

Headcount range

251–500 employees

Ownership category

akta.pro rank

Product category

AI Data Annotation Services

NAICS

Custom Computer Programming Services (541511), Other Computer Related Services (541519)

SIC

Services-Computer Programming Services (7371), Services-Computer Programming, Data Processing, Etc. (7370)

akta.pro primary industry

Data Labeling & Annotation Services (HDAAALAB)

akta.pro secondary industries

Annotation Tooling & Workflow Management (HDAAALAC), Safety, Alignment & Content Moderation (Guardrails, Red Teaming) (HDAAACAI), Responsible AI, Security & Privacy Platforms (Safety, Guardrails, PII) (HDAEANAG)

Keywords

• Data annotation services
• AI training data
• Human-in-the-loop labeling
• Multimodal data annotation
• RLHF evaluation services

Headquarters

HQ city

Madrid

HQ country

Spain

HQ region

Europe

Offices3 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Infrastructure, Marketing or Sales, Technology or R&D, Others

Revenue model

1. Data Annotation Services: Professional services for data sourcing, collection, annotation, and validation. Pricing models include hourly-based and unit-based approaches depending on client preferences and data type.
2. Pilot Programs: Fixed-fee pilot programs ($3,000 for two weeks) that provide tailored annotation and validation services to demonstrate value for new customers.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels6 records

Core offering

Sigma AI provides human-in-the-loop data annotation, sourcing, and validation services for AI training, delivered through six service lines (Sigma Data, Sigma Integration, Sigma Meaning, Sigma Truth, Sigma Protection, and Sigma Perception). A 25,000+ in-house annotator workforce covering 500+ languages executes text, audio, image, video, and multimodal labeling for LLM training, RLHF, ground truth verification, red teaming, and bias detection. Services are backed by ISO 27001/SOC 2 Type II certified secure facilities and proprietary annotation tooling for confidential enterprise workloads.

Product overview

Sigma AI provides a platform-plus-six-modules architecture for human-in-the-loop data annotation services. The core offering consists of six interconnected service lines: Sigma Data (data sourcing, collection, and synthesis), Sigma Integration (multimodal annotation connecting audio, image, video, and text), Sigma Meaning (linguistic and cultural annotation across 700+ languages), Sigma Truth (ground truth verification and factual accuracy), Sigma Protection (security, red teaming, and PII compliance), and Sigma Perception (tone, emotion, and intent annotation). A sister company, Sigma Cognition, provides AI consultancy and custom solution development. The company operates a 25,000+ annotator workforce and serves global tech leaders with human expert annotation to evaluate and enhance generative AI systems.

Differentiator

Problem solved

Functional benefit

Brands

• Sigma Cognition: AI consultancy and full-service proof-of-concept and solutions provider that extends in-house AI capabilities for companies venturing into AI.

Products and services

• Sigma Data Data sourcing, collection, annotation, and synthesis service providing high-quality, diverse, multilingual datasets. Covers data enrichment, human annotation, synthetic data generation, and bias mitigation for training AI models.
• Sigma Integration Multimodal annotation service connecting images, video, audio, and text into cohesive datasets. Includes prompt engineering, iterative response refinement, and RLHF for context-aware AI training.
• Sigma Meaning Linguistic annotation service covering multilingual transcription, translation, and cultural calibration. Supports 700+ languages and dialects with phonetic, structural, and contextual enrichment.
• Sigma Truth Ground truth verification and factual accuracy service. Expert human annotators validate facts, correct inaccuracies, prevent hallucinations, and ensure attribution using research-validate-rewrite workflows.
• Sigma Protection AI safety and security service including red teaming, PII detection and removal, ethical data sourcing, and data residency compliance. Provides secure facilities (clean rooms) for confidential data annotation.
• Sigma Perception Emotion and tone annotation service that captures intent, cultural nuance, and user expectation. Side-by-side evaluation, bias detection, and content moderation for empathetic AI outputs.
• Sigma Cognition AI consultancy and full-service proof-of-concept provider that extends in-house AI capabilities, supporting teams in developing, training, and delivering custom AI solutions.

Quantifiable outcome

• 20% enhanced fraud detection with optimized NLP models
• +5 more outcomes

Named customers5 records

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability12 records

Feature3 records

Partnerships

Eight partnerships are on record, tiered core and minor.

• Sigma CognitioncoreStrategic or Co-development PartnerSister company that is an AI consultancy and full-service proof-of-concept and solutions provider. Extends in-house AI capabilities for companies venturing into AI, supporting teams in developing, training, and delivering custom AI solutions.
• AccemminorOthersSocial partner for diversity initiatives and immigrant/refugee employment support. Sigma trains employees to avoid bias and assists immigrants and refugees to support their employment.
• Fundación Juan XXIIIminorOthersSocial Employment Center partnership supporting people with disabilities.
• Fundación RandstadminorOthersDisability support program partnership for social employment.
• AFANIASminorOthersSocial Employment Center partnership supporting people with disabilities.
• FilantrópicominorOthersPartnership for social impact and employment support.
• Misiones SalesianasminorOthersDonations to support training projects for young people in Africa, Americas, Europe, and Middle East, and Ukrainian refugees.
• ReforestaminorOthersEnvironmental partnership through which employees planted more than 80 native trees through company-sponsored volunteer days.

Scale indicators10 records

Recent moves6 records

Expansion highlights5 records

Emerging players

• Labelbox: Labelbox is an AI data platform combining labeling tooling with optional managed services. It is comparable to Sigma AI at the platform/services intersection, though more weighted toward tooling than pure-service delivery.

Direct peers

• Scale AI: Scale AI is the largest pure-play AI data-labeling platform, offering annotation and evaluation services to frontier AI labs and enterprises. It is the most direct competitor to Sigma AI in gen-AI data labeling, RLHF, and red-teaming.
• Surge AI: Surge AI is a premium human-data platform focused on RLHF and nuanced labeling for frontier LLMs. It competes head-to-head with Sigma AI in subjective-evaluation and preference-data work for gen-AI labs.
• iMerit: iMerit is a specialized data-labeling provider with skilled in-house annotators focused on computer vision, NLP, and medical AI. It competes with Sigma AI on quality-focused, domain-expert annotation for enterprise AI teams.
• CloudFactory: CloudFactory provides a managed workforce for AI data labeling, focusing on computer vision and NLP for ML teams. It is a comparable peer for Sigma AI's enterprise annotation and managed-workforce go-to-market.
• Sama (Sand Technologies): Sama delivers ethical, high-quality data annotation and model evaluation services, with an emphasis on computer vision and AI validation. It overlaps with Sigma AI on enterprise annotation quality and impact-sourcing positioning.
• Defined.ai: Defined.ai offers pre-built and custom datasets plus data annotation services for ML teams, with multilingual coverage. It competes with Sigma AI in training-data marketplaces and enterprise annotation services.

Broad incumbents

• Telus International (Lionbridge AI): Telus International (formerly Lionbridge AI) provides enterprise-scale AI data solutions including annotation, localization, and multilingual data. It is a broad incumbent comparable to Sigma AI on multilingual AI data services for global enterprises.
• Appen: Appen is a publicly listed incumbent in data annotation and dataset services with a global crowd. It overlaps directly with Sigma AI across multilingual data collection and traditional AI training data but at a much larger, crowdsourced scale.
• Innodata: Innodata provides data engineering and AI training-data services for large enterprises and governments. It competes with Sigma AI on enterprise annotation contracts, particularly in regulated verticals.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/sigma-ai

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles9 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sigma AI