What is Redact PDF?
Redact PDF draws opaque black rectangles over specified page regions using percentages measured from the top-left. Multiple rectangles can be added across pages before a new PDF is downloaded.
This implementation performs visual blackout only. It does not remove underlying text, images, metadata, annotations, content streams, hidden layers, or other recoverable data. It is not suitable as the sole redaction method for sensitive information.
Why Use This Tool?
Visual blackout can be useful for a non-sensitive mockup, review marker, or display copy where hiding appearance—not securely deleting information—is the actual goal.
- Cover one or more visible page regions
- Address regions by page and percentage
- Create an obvious black visual mask
- Process the file locally
How Does This Tool Work?
For each rectangle, the tool converts x, y, width, and height percentages to page coordinates and draws a black shape on top of existing content. It then saves the modified PDF.
Because the original content remains beneath the new drawing operation, copying text, removing overlays, inspecting content streams, or using another parser may reveal covered information.
Understanding Your Results
A black area in a viewer only proves that an overlay is visible. It does not prove that the underlying information was removed. Cropping, flattening supported form fields, or adding another overlay does not automatically provide secure redaction.
Why Tracking This Matters
Failed redaction can expose personal data, privileged communications, trade secrets, health information, financial records, or protected identities. For consequential disclosure, use a trusted redaction workflow that removes content and validates the sanitized file.
Benefits of Using Redact PDF
- Multiple visual blackout regions
- Page-specific percentage coordinates
- Opaque black overlays
- No server upload
- Clear visual-redaction limitation
- Separate output preserves the source
How Is the Result Calculated?
The tool scales each percentage by the selected page dimension. The top-origin y value is converted to the PDF’s bottom-origin coordinate system.
PDF y = page height − (top ratio + height ratio) × page height
- Top ratio
- Y percentage divided by 100.
- Height ratio
- Rectangle height percentage divided by 100.
Tips for Better Results
- Do not use this tool alone for confidential disclosure.
- Use a content-removing redaction product for sensitive data.
- Search and copy text from the output as a basic warning check.
- Inspect metadata, attachments, comments, and layers separately.
- Have another authorized person verify consequential redactions.
- Retain the unredacted original in access-controlled storage.
Conclusion
Redact PDF creates visual blackouts, not secure deletion. Use it only when an overlay is sufficient; for confidential, legal, or regulated material, use a content-removing redaction process and validate the sanitized PDF before release.