How it works
The PDF Redaction tool permanently covers sensitive content in a PDF with solid black rectangles — a process required for legal discovery, FOIA responses, medical record sharing, and any disclosure that requires hiding personally identifiable information (PII), protected health information (PHI), or privileged content.
How redaction works: you upload the PDF, which renders page-by-page as a canvas preview. You draw rectangles over the content you want to redact (click and drag). Each rectangle is stored as a relative coordinate on that page. When you apply redactions, black-filled rectangles are drawn directly into the page content using pdf-lib, permanently covering the target areas.
Relative coordinates: redaction positions are stored as fractions of page width and height (not pixel coordinates), so they scale correctly to any PDF page size.
Important notes on PDF redaction: - This tool performs visual redaction by drawing over content — the underlying text data in the PDF is NOT deleted. For legally defensible redaction that removes the underlying text, the document should be saved as a flattened PDF after applying the black rectangles. Use the PDF Flatten tool on the output. - Standard "black rectangle over text" redaction is sufficient for most purposes and matches the output of Adobe Acrobat Standard's redaction feature, which also draws over content and requires a separate "Sanitize Document" step to remove underlying data.
To redact multiple areas: draw each rectangle on the page, then navigate to other pages and draw there too. All rectangles accumulate in the queue and are applied simultaneously when you click Apply Redactions.
Privacy: rendering and rectangle application run in the browser. No page content is transmitted.
Frequently Asked Questions
- The black rectangles applied by this tool visually cover the selected areas, meeting the basic requirement of redaction for most purposes. However, the underlying PDF text stream is not modified — the text data remains in the file. For legally defensible redaction (court submissions, FOIA responses, HIPAA compliance), run the output through the PDF Flatten tool immediately after redacting. Flattening merges the black rectangles into the page content and eliminates the original interactive layer, though a full text-layer removal requires a dedicated redaction tool that scrubs the underlying content stream.
- Yes. Navigate to each page using the arrow controls, draw redaction rectangles on that page, then navigate to the next page. Each page's rectangles are stored independently in memory. All redactions across all pages are applied together when you click Apply Redactions.
- The coordinates are stored as fractions of the page width and height (0.0 to 1.0), so they are resolution-independent and scale correctly to any PDF page size. The canvas preview scales the page to fit your browser window — drawing precision depends on your canvas display size, but typical accuracy is within 1–2% of the page dimension, which is sufficient for most redaction use cases.
- Click 'Clear all' to remove all queued rectangles. There is no per-rectangle undo — if you clear all and want to redraw only some, re-draw all the rectangles you need. The clear is only for the in-memory queue before you click Apply — once the redacted PDF is downloaded, the rectangles are baked in.