Privacy-First PDF Redaction

Our Mission

PDF Redact Free exists for one reason: to make true, permanent PDF redaction accessible to everyone, for free, without privacy trade-offs.

Every week, people share bank statements, tax forms, Social Security documents, and medical records after attempting to "redact" them with black highlighters or annotation layers — methods that leave the underlying data fully recoverable. At the same time, commercial tools that do proper redaction (Adobe Acrobat Pro, Nuance Power PDF, Foxit PhantomPDF) cost hundreds of dollars per year.

We fixed that. PDF Redact Free is free, requires no account, and runs entirely inside your web browser.

How Our Technology Works

PDF Redact Free is built on powerful open-source JavaScript and WebAssembly libraries:

• Mozilla PDF.js: Renders your PDF pages directly to HTML5 canvas elements inside the browser, with full fidelity to the original document layout.
• pdf-lib: Modifies the PDF document structure directly, burning permanent opaque black rectangles into the content stream at the precise coordinates you specify.

When you drop a PDF into our tool:

• The file is read into your device's browser memory (RAM) as a local ArrayBuffer.
• PDF.js renders it to canvas — completely locally.
• When you draw a redaction box, we record the exact canvas coordinates.
• On export, we use a coordinate inversion formula to convert canvas pixel coordinates to PDF user-space coordinates (PDF coordinates originate at the bottom-left, while HTML5 canvas originates at the top-left).
• pdf-lib draws permanent black vector rectangles at those coordinates in the PDF's content stream.
• The resulting redacted PDF bytes are downloaded directly to your device.

At no point does any byte of your document travel to an external server. There is no cloud storage, no backend database, and no server queue. Your files stay strictly in your local browser memory.

The Privacy & Sustainability Model

Most online PDF tools upload your file to their servers, process it remotely, and let you download the result. This means your sensitive document — with all its private information intact — has been transmitted across the internet and temporarily hosted on someone else's hardware.

PDF Redact Free eliminates this risk by design. Because all document processing is executed locally on your device, we have no server processing costs for files. To keep the service 100% free and sustainable without charging user subscriptions, we display standard web advertising managed by third-party partners like Google. These advertising systems only operate at the web page level and can never see, access, or read your PDF documents.

Who We're For

PDF Redact Free is built for anyone who needs to share a PDF safely:

• Individuals sharing bank statements for loan or rental applications
• Freelancers and contractors redacting client details before sharing invoices
• Journalists and researchers protecting sources in document scans
• HR professionals redacting salary or SSN information from shared forms
• Legal professionals preparing documents for public filing
• Anyone sharing tax documents (W-2, 1099, 1040) with sensitive numbers hidden