Privacy-First · Permanent · Free

Smart & Secure
PDF Redaction Tool

Permanently black out emails, phone numbers, card numbers and any sensitive content from your PDF — right in your browser. No server. No account. No risk.

Instant Redaction100% PrivateWorks Offline

How to Redact a PDF in 3 Steps

No software installation. No account. Everything runs locally — your documents never leave your device.

  1. 1

    Upload Your PDF

    Drag and drop or click to select a PDF. The file is read directly by your browser — nothing is transmitted to any server.

  2. 2

    Place Redaction Blocks

    Use Smart Redact to auto-detect emails, phone numbers and card numbers, or click anywhere on the document in Manual Mode to place a precisely-sized block. Adjust width, height, colour and opacity to suit.

  3. 3

    Apply & Download

    Click Apply & Download. pdf-lib burns the redaction rectangles permanently into the PDF page. The downloaded file contains no recoverable trace of the hidden content.

Permanent Redaction

Rectangles are burned into the PDF structure via pdf-lib. The text beneath cannot be selected, searched, or recovered.

Smart Auto-Detect

Regex scanning across all pages automatically finds and marks emails, phone numbers, and 13–16 digit card numbers.

Zero Data Exposure

All processing happens inside your browser sandbox. Your confidential PDFs are never uploaded to any server.

Manual Precision

Click anywhere on any page to drop a custom block. Fine-tune width, height, colour, and opacity before committing.

Why PDF Redaction Matters — and Why Most Tools Get It Wrong

Many people cover sensitive text by drawing a black rectangle in a PDF editor or adding an opaque annotation — then share the file assuming the information is hidden. In reality, the original text layer is still present in the document and can be revealed by removing the annotation, running a text search, or simply copying the "blacked-out" area into a text editor.

True PDF redaction means the hidden content is structurally removed or overwritten in the output file — not just covered with a coloured shape. This tool uses pdf-libto draw filled rectangles directly onto the page content stream, replacing the text at the byte level so that no recovery is possible from the downloaded document.

Browser-Based Redaction: No Upload, No Exposure

Most online redaction services require you to upload your document to a remote server. For files containing personal data, financial records, legal correspondence, or healthcare information, that upload creates a serious privacy and compliance risk — even if the provider deletes the file afterwards.

This tool is built differently. PDF.js renders the document locally for preview and text extraction. pdf-lib applies the redaction blocks and generates the output — all inside your browser's sandbox. Your file is never transmitted, stored, or logged. It works offline after the first load.

Auto-detect emails, phones & card numbers
Manual click-to-place blocks on any area
Adjustable width, height, colour & opacity
Undo last mark or clear all with one click
Multi-page support — redact any page
Zero file uploads — 100% browser-based
No account, subscription, or watermark
Completely free with no hidden fees

Who Needs a PDF Redaction Tool?

Legal Professionals

Redact client names, case numbers, and privileged information before sharing discovery documents or court filings with third parties.

HR & Finance Teams

Remove salary figures, bank account numbers, national ID numbers, and personal addresses from contracts and payslips before archiving.

Healthcare & Compliance

Scrub patient identifiers from clinical notes, insurance forms, and medical records to meet GDPR, HIPAA, and data-minimisation obligations.

Journalists & Researchers

Protect source identities and redact sensitive passages from leaked documents before publication or sharing with editors.

Verification recommended: After downloading, open the redacted PDF in a viewer and attempt to select text in the blacked-out areas to confirm the content is no longer accessible. For the highest-assurance legal or regulatory workflows, consider a dedicated professional redaction product.

Frequently Asked Questions

Does redaction permanently remove the data from my PDF?+
Yes. The tool uses pdf-lib to draw filled rectangles directly onto the PDF page at the exact coordinates of each redaction mark. The original text layer beneath is overwritten in the output file — it cannot be selected, copied, or revealed by removing a colour layer. Note: for the highest-assurance workflows (e.g. legal discovery), always verify the output in a PDF reader.
Is my document uploaded to any server?+
No. Every operation — loading, scanning, placing redaction blocks, and generating the output — runs entirely inside your browser using PDF.js and pdf-lib. Your file never leaves your device.
What does Smart Redact detect automatically?+
Smart Redact scans every page's text layer and applies regex patterns to find email addresses (e.g. user@domain.com), phone numbers (including international formats), and card numbers (13–16 digit sequences). It then places precisely-sized redaction blocks over each match.
Can I redact scanned PDF documents?+
Scanned PDFs contain images rather than selectable text, so the Smart Redact auto-detection will not find matches. However, you can still use Manual Mode — click anywhere on the page to place a custom-sized redaction block over sensitive content visible in the image.
Can I undo a redaction before downloading?+
Yes. Use the Undo button to remove the most recent redaction mark one at a time, or Clear All to remove every mark on all pages. Changes are only committed when you click Apply & Download.
Is there a limit to how many redactions I can place?+
There is no limit. You can place as many manual or auto-detected redaction blocks as needed, across any number of pages, before downloading the final PDF.

If MERAPDF helped you convert, compress, or secure your documents, you can support its development. Your contribution helps keep this project always free, offline, and privacy-first.

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