Document-based PII overview

Document-based PII is a preview feature in Azure AI Language Personally Identifiable Information (PII) detection. It helps you detect and redact sensitive data directly in native document files, including Microsoft Word and PDF files, without building your own text extraction and reconstruction pipeline.

This feature uses an asynchronous API workflow and returns redacted output that preserves document structure and formatting. You can use it when document fidelity is important for compliance review, sharing, analytics, and downstream AI workflows.

At a glance

Document-based PII provides the following capabilities:

• Native document redaction for .pdf, .docx, and .txt files.
• Preserved layout in output documents, including font, spacing, and color.
• A single asynchronous API workflow for extraction, detection, and redaction.
• Enterprise-ready outputs: a redacted document and a structured JSON result.

Video demonstration

In this video, we introduce the PII detection service and show you how it detects and redacts sensitive data directly from native documents while preserving file structure and formatting. We also cover common use cases, supported formats, and how to get started with document-based PII in Azure AI Language:

Closed captions are available for this video.

Why use document-based PII?

Many custom pipelines require multiple steps to extract text, run detection, and reconstruct document output. Document-based PII simplifies this flow with a single asynchronous API pattern and output artifacts designed for document-processing systems.

Document-based PII is especially useful when you need to:

• Redact PII in .pdf, .docx, and .txt files.
• Preserve document layout for downstream business processes.
• Generate structured JSON output for auditing and integration.

Document-based PII uses the same predefined PII categories as text PII, including entities such as addresses, phone numbers, and credit card numbers.

What it returns

When a job succeeds, you receive:

• A redacted document in your target storage container.
• A JSON result file with detected entities, categories, confidence scores, and processing metadata.

How it works

Document-based PII uses an asynchronous workflow:

1. Submit a job with source and target storage locations.
2. Poll the job status by using the operation location.
3. Retrieve output artifacts from your target storage location.

For implementation details and request samples, see Detect and redact Personally Identifiable Information in native documents.

How it differs from other PII feature types

All PII feature types use predefined entity categories, but they optimize for different input types:

• Document-based PII is optimized for native-file redaction workflows and file output fidelity.
• Text PII is optimized for direct string-based input and app integration.
• Conversation PII is optimized for turn-based and transcript-oriented conversational input.

Common use cases

Document-based PII is designed for enterprise and regulated-industry workflows where teams need to anonymize files before storage, analytics, external sharing, or downstream AI processing.

Typical examples include:

• Court records and legal documentation.
• Government forms and internal records.
• Financial documents.
• Internal enterprise documentation workflows.

Supported formats and limits

Document-based PII accepts native file formats directly, without requiring text preprocessing. The following table lists the supported formats:

The following input constraints apply:

The following content types are not supported:

See language support and quotas and limits for current language coverage and service limit details.

Pricing

Document-based PII redaction uses Azure AI Language pricing. For current pricing details, see Azure AI Language pricing.

Next steps

Use the following references to continue implementation:

• Create SAS tokens for storage containers
• Create a managed identity for storage containers