Highlight PDF — mark important parts

Combine unlimited PDF files instantly. 100% private, no uploads, no file size limits.

Drop files here
or click to browse — any number of files

Highlight PDF Online — Mark Important Text and Areas

Permanently obscure sensitive information in PDF documents by drawing opaque rectangles over text, images, or data. PDFree's redaction tool covers content visually — perfect for sharing documents where certain information must remain confidential.

How Redaction Works

Drag across the PDF preview to select areas to cover. PDFree draws black (or custom color) rectangles over those regions. The rectangles become part of the PDF content — they cannot be removed or hidden to reveal underlying text.

Important distinction: This is visual coverage, not cryptographic deletion. The original content remains in the PDF file structure but is visually obscured. For most use cases (legal compliance, public records requests, privacy protection), this is exactly what's needed — the content cannot be seen or copied, but the document structure remains intact.

When to Use Redaction

Legal Documents: Obscure names, addresses, social security numbers, or account numbers before filing public court documents or responding to FOIA requests.

Medical Records: Remove patient identifying information to create de-identified records for research or case studies (HIPAA compliance).

Financial Statements: Hide account numbers, transaction details, or balances when sharing bank statements for loan applications or background checks.

Business Contracts: Redact pricing, terms, or confidential clauses when sharing contract templates or portions with third parties.

Government Documents: Public records officers use redaction to protect privacy while releasing information under transparency laws.

Usage Instructions

  1. Upload the PDF — a preview renders in your browser
  2. Click and drag to draw a redaction rectangle over sensitive text or images
  3. Repeat for all areas needing coverage (up to 5 areas per page to prevent accidental over-redaction)
  4. Click "Clear all" if you need to start over
  5. Download the redacted PDF — black rectangles are now permanent

Security Considerations

What Redaction Does:

  • ✅ Prevents visual viewing of covered content
  • ✅ Prevents text selection/copying of covered content
  • ✅ Works in all PDF readers (rectangles are standard PDF drawing objects)

What Redaction Does NOT Do:

  • ❌ Does not delete content from the PDF file structure (forensic tools can extract underlying text)
  • ❌ Does not remove metadata — use the Metadata tool on the PDFree homepage separately
  • ❌ Does not prevent determined adversaries with specialized software from accessing original content

⚠️ Legal Redaction: For documents subject to legal proceedings or classified information, consult your compliance or legal team. Some jurisdictions require certified redaction tools that cryptographically delete content. PDFree provides visual coverage suitable for most business and privacy use cases but is not certified for classified government documents or high-security legal contexts.

Privacy & Processing

Your PDF never leaves your browser. The redaction rectangles are drawn using pdf-lib's content stream API — all processing happens locally in JavaScript. No server sees your sensitive document or learns what you chose to redact.

Related Tools