How to Redact Documents Before Sending Them to AI

Use LocalMask to redact PDFs, Word files, Excel sheets, scans, images and copied text locally before using AI tools.

How to Redact Documents Before Sending Them to AI

Use this guide when you want to send a contract, report, spreadsheet, scan, screenshot or copied text to an AI tool, but the material contains names, phone numbers, company names, addresses, accounts or internal business details.

The goal is not to black out everything. For AI work, stable aliases usually work better: the AI can still understand relationships without seeing the original identifiers.

Step 1: Import files and choose categories and redaction mode

Add the files on the home screen. PDFs, Word files, Excel sheets, CSV files, scans and images can be processed together. For text copied from a web page, chat or email, use clipboard redaction.

Add files and choose redaction categories

For AI preparation, commonly enable:

  • Names, phone numbers, emails and addresses
  • Company names and business identifiers
  • Financial accounts, amounts and dates
  • Seals, faces, QR codes and barcodes
  • Custom terms such as customer names, project names and internal codes

Choose the redaction mode before starting. For AI tasks, stable aliases usually work best:

  • Jane Smith -> Person A
  • Acme Ltd -> Company A
  • A real address -> Address A

Use partial or full masking for phone numbers, ID numbers and account numbers when the exact value is not useful for the AI task.

Step 2: Review detected hits

After detection, open the review view and inspect the hit list. Do not export immediately.

Review detected hits

Check whether:

  1. Names, companies and contact details were detected.
  2. Public terms were incorrectly selected.
  3. Headers, footers, tables, attachments and scanned pages were missed.
  4. The same person or company uses a consistent alias.

If something is missing, mark it manually or add it to the custom dictionary.

Step 3: Search for known sensitive terms

Search for terms you already know are in the file: customer names, project names, phone suffixes, email domains or internal codes.

Search for known terms

Search is a verification step. If the term still appears unredacted, fix it before export.

Step 4: Preview the redacted result

Open the redaction preview and read the output as the AI will see it.

Preview redacted content

Make sure the document is still understandable, aliases are stable, and visual content such as faces, seals and QR codes is not exposed.

Step 5: Export, then send the redacted copy

Export the redacted file or copy the redacted text, then send that version to the AI tool. Do not upload the original file by mistake.

If the AI output contains aliases such as Person A or Company B and you need to restore them locally, use alias restoration.

Restore aliases locally

Before sending, search the exported copy for the original names, phone numbers and customer names one more time.

Local document redaction

LocalMask helps detect, review and export redacted copies locally before AI use or external sharing.

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