Redact PDF
Draw black boxes over sensitive content. Redaction is permanent and processed on our server.
Permanent Redaction
Upload a PDF, then draw boxes over sensitive content
How It Works
Upload your PDF
Drop in any PDF containing sensitive information — contracts, medical records, financial documents.
Select areas to redact
Draw redaction boxes over the text, numbers, or images you want to permanently remove. Works across all pages.
Apply and download
Click Apply Redactions — the selected content is permanently removed from the file structure, not just hidden.
Why Most PDF Redaction Fails — and How to Do It Right
The most dangerous redaction mistake: drawing a black rectangle over sensitive text in a PDF editor, saving the file, and thinking the information is gone. It isn't. The text is still present in the PDF file structure — it's just hidden behind a black box. Anyone with a PDF editor, Adobe Acrobat, or even a basic text editor can remove the box and read the original content.
High-profile redaction failures have exposed classified government documents, personal medical records, and confidential legal filings — all because someone drew a black box instead of truly redacting.
What True Redaction Does
Genuine redaction permanently removes the underlying data from the PDF file structure and replaces it with a solid fill. After proper redaction:
- The text cannot be selected or copied
- The text does not appear in accessibility tools or screen readers
- The content cannot be recovered by any PDF editor or forensic tool
Legal and Compliance Use Cases
- Legal filings — court rules often require redaction of SSNs, dates of birth, and minor children's names
- HIPAA compliance — medical records shared outside a covered entity must have PII removed
- GDPR data requests — documents containing third-party personal data must be redacted before disclosure
- Financial disclosures — account numbers, routing numbers, and card numbers in shared statements
- HR documents — salary details and personal employee information before sharing job descriptions or org charts
How to Verify Your Redaction Worked
After downloading your redacted PDF, open it and try to:
- Click and drag to select text in the redacted area — you should be unable to select anything
- Copy the entire document text (Ctrl+A, Ctrl+C) and paste into a text editor — the redacted content should not appear
- Open in Adobe Acrobat's "Find" (Ctrl+F) and search for a redacted term — it should return no results
If any of these tests surface redacted content, the redaction was applied as an overlay, not a true removal. Re-upload and use SynthPDF's tool for proper redaction.
Frequently Asked Questions
A black box overlay is just a shape drawn on top of the text — the text underneath is still in the PDF and can be read by anyone who removes the box or opens the file in a text editor. True redaction removes the underlying text from the PDF file structure entirely.
No. Our tool removes the content from the PDF object structure, not just visually covers it. There is no recoverable data underneath the redaction marks.
Yes — scanned PDFs are image-based. Redaction removes the pixel data in the selected area from the image layer.
Yes — add redaction areas to any number of pages before applying. All redactions are applied together in one pass.
Our tool performs permanent content removal suitable for compliance workflows. For legally sensitive use cases, always verify the output by attempting to copy text from the redacted areas after downloading.
Your file is processed server-side and deleted from our servers within 30 minutes. We do not retain or read document content.