ai4privacy/pii-masking-openpii-1m

OpenPII 1M — Multilingual PII Masking Dataset

Overview

The OpenPII 1M dataset is a large-scale, multilingual collection of 1,428,143 synthetic text examples with fine-grained PII (Personally Identifiable Information) annotations, spanning 23 European languages and 19 entity types.

Built to advance open research in privacy-preserving NLP, this dataset enables the development and benchmarking of Named Entity Recognition (NER) models, token classification pipelines, and data masking systems that work across languages and borders.

Each example contains the original text, a masked version with labeled placeholders, span-level annotations, and pre-computed BIO token labels compatible with transformer-based models (mBERT, XLM-R, ModernBERT, etc.).

Dataset Details

Property	Value
Total Examples	1,428,143
Train Split	1,143,397
Validation Split	284,746
Unique Labels	19
Languages	23
Total Annotations	10,328,208
Format	JSON Lines (.jsonl)
License	CC-BY-4.0
Contact	enterprise@ai4privacy.com

Language Coverage

The dataset spans 29 regions — 25 European countries plus Canada (CA), United States (US), Mexico (MX), and India (IN).

Label Taxonomy (19 Labels)

Label	Count	Description
DATE	1,218,939	Dates and temporal references
GIVENNAME	1,205,300	First / given names
SURNAME	1,056,355	Last / family names
EMAIL	769,479	Email addresses
CITY	721,890	City names
TITLE	670,650	Personal titles (Mr, Dr, etc.)
TELEPHONENUM	574,865	Phone numbers
AGE	512,150	Age values
STREET	484,891	Street names
BUILDINGNUM	476,224	Building / house numbers
ZIPCODE	443,413	Postal / ZIP codes
IDCARDNUM	333,065	National ID card numbers
CREDITCARDNUMBER	320,504	Credit card numbers
DRIVERLICENSENUM	286,935	Driver's license numbers
GENDER	277,496	Gender identifiers
TAXNUM	266,967	Tax identification numbers
SEX	256,019	Biological sex
SOCIALNUM	246,414	Social security numbers
PASSPORTNUM	206,652	Passport numbers

Data Structure

Each line in the JSONL files is a JSON object:

{
  "source_text": "John Smith lives at 42 Rue de Rivoli, 75001 Paris.",
  "masked_text": "[GIVENNAME_1] [SURNAME_1] lives at [BUILDINGNUM_1] [STREET_1], [ZIPCODE_1] [CITY_1].",
  "privacy_mask": [
    {"value": "John", "start": 0, "end": 4, "label": "GIVENNAME"},
    {"value": "Smith", "start": 5, "end": 10, "label": "SURNAME"},
    {"value": "42", "start": 20, "end": 22, "label": "BUILDINGNUM"},
    {"value": "Rue de Rivoli", "start": 23, "end": 36, "label": "STREET"},
    {"value": "75001", "start": 38, "end": 43, "label": "ZIPCODE"},
    {"value": "Paris", "start": 44, "end": 49, "label": "CITY"}
  ],
  "split": "train",
  "uid": "openpii-abc123",
  "language": "fr",
  "region": "FR",
  "script": "Latn",
  "mbert_tokens": ["[CLS]", "John", "Smith", "lives", "..."],
  "mbert_token_classes": ["O", "B-GIVENNAME", "B-SURNAME", "O", "..."]
}

Use Cases

• NER Research: Train and evaluate multilingual token classification models for PII detection
• Privacy-Preserving NLP: Build data anonymization and masking pipelines across 23 languages
• Multilingual Benchmarking: Compare PII detection models across language families (Germanic, Romance, Slavic, Finno-Ugric, Baltic, Hellenic)
• Compliance Tools: Develop systems for GDPR, CCPA, and other data protection regulations
• AI Safety: Prevent language models from memorizing or exposing sensitive personal information

Extended Taxonomies

This dataset covers the 19 core identity labels. For research or enterprise applications requiring extended label taxonomies — including 82+ labels across health (PHI), financial (PFI), digital (PDI), work (PWI), and location (PLI) categories — contact our team:

📧 Email: enterprise@ai4privacy.com 🌐 Website: www.Ai4Privacy.com 🔗 Contact Form: https://forms.gle/oDDYqQkyoTB93otHA

Related Datasets

Dataset	Labels	Languages	Size	Category
pii-masking-2m	82+	24	2M+	Full EPII taxonomy
phi-masking-100k	20	8	100K+	Personal Health Information
pfi-masking-100k	20	8	100K+	Personal Financial Information
pdi-masking-100k	20	8	100K+	Personal Digital Information
pwi-masking-100k	20	8	100K+	Personal Work Information
pli-masking-100k	20	8	100K+	Personal Location Information

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p5y Data Analytics

This dataset is built on the p5y framework - think of it as i18n but for privacy. Just as i18n (internationalization) translates content into different locales, p5y translates sensitive data into privacy-safe formats through a standardized 3-step approach:

1. Awareness - Scan and markup private entities in unstructured text, producing a structured privacy mask with entity types, distribution, density, and risk assessment.
2. Protection - Control identified personal data through masking, pseudonymization, or k-anonymization, tailored to the specific use case and regulatory requirements.
3. Quality Assurance - Measure remaining privacy risk after anonymization, evaluating de-anonymization risks through expert annotation and automated assessment.

Learn more at p5y.org

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About Ai4Privacy

At Ai4Privacy, we are building the global seatbelt for Artificial Intelligence — enabling innovation while safeguarding personal information. We develop state-of-the-art datasets and tools for privacy-preserving AI.

• Newsletter & Updates: www.Ai4Privacy.com
• Join our Community: Discord
• Contribute/Feedback: Open Data Access Form

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Licensing and Terms of Use

• License: CC-BY-4.0. Copyright © 2026 Ai Suisse SA.
• Permitted Use: Research, commercial use, redistribution, and modification — subject to attribution requirements under CC-BY-4.0.
• Attribution: When using this dataset, please credit "Ai4Privacy / Ai Suisse SA" and link to this repository.
• Responsible Use: Use must comply with all applicable data privacy laws and regulations. This dataset contains synthetic PII only — no real personal data is included.
• Citation:

  @dataset{ai4privacy_openpii_1m_2026,
    author = {Ai4Privacy},
    title = {OpenPII 1M — Multilingual PII Masking Dataset (19 Labels, 23 Languages)},
    year = 2026,
    publisher = {Hugging Face},
    url = {https://huggingface.co/datasets/ai4privacy/pii-masking-openpii-1m}
  }
  

Legal Disclaimer

No Warranty & Use at Your Own Risk: This dataset is provided "as is" without warranties of any kind. Ai4Privacy and Ai Suisse SA make no representations regarding accuracy, completeness, or suitability. Use is at your own risk.

No Liability: Ai4Privacy, Ai Suisse SA, and affiliates shall not be liable for any damages (direct, indirect, consequential, etc.) arising from the use or inability to use this dataset.

Compliance & Responsibility: Users are solely responsible for ensuring their use complies with all applicable laws, regulations, and ethical guidelines, including data privacy laws (e.g., GDPR, CCPA) and AI regulations. This dataset contains synthetic PII only — no real personal data is included.

Ai4Privacy is a project affiliated with Ai Suisse SA.