# Just Redact

## Project Overview

**Just Redact** is a secure, client-side web application designed for permanently redacting sensitive information from PDF documents. 

Unlike many online PDF tools, Just Redact processes files entirely within the user's browser using WebAssembly (via PDF.js). **No files are uploaded to any server.** This ensures complete privacy for financial, legal, and medical documents.

**Key Features:**
*   **Local-Only Processing:** Zero server uploads.
*   **True Flattening:** To ensure redactions are permanent and non-reversible, the application converts each PDF page into a high-resolution image (rasterization) during export. This physically destroys the text data underneath the redaction boxes, preventing recovery via copy-paste or text search.
*   **Dual Redaction Modes:**
    *   **Draw:** Manually draw boxes over sensitive areas (images, tables, headers).
    *   **Select Text:** Highlight text to automatically create redaction boxes over the selection.

## Tech Stack

The project is built with standard web technologies and relies on CDNs for libraries. No complex build chain is required.

*   **Frontend:** HTML5, CSS3, Vanilla JavaScript.
*   **Styling:** 
    *   `index.html`: Tailwind CSS (via CDN).
    *   `redact.html`: Custom internal CSS.
*   **Libraries (CDNs):**
    *   **PDF.js:** For parsing and rendering PDF documents in the browser.
    *   **jsPDF:** For generating the final "flattened" PDF document from canvas images.

## Project Structure

*   **`index.html`**: The landing page. Contains marketing copy, "How it Works", FAQ, and SEO metadata. Styled with Tailwind CSS.
*   **`redact.html`**: The core application. Contains the logic for file loading, PDF rendering, redaction interaction (drawing/selecting), and the flattening/export process.
*   **`just-redact.png`**: Application screenshot/logo asset.
*   **`statement_sample.pdf`**: A sample PDF file provided for testing the redaction workflow.

## Development & Usage

### Running the Project

Since this is a static site with no build step, you can run it directly.

1.  **Simple Open:** You can open `index.html` or `redact.html` directly in your web browser.
    *   *Note:* The application requires an internet connection to load the libraries from CDNs (Tailwind, PDF.js, jsPDF).

2.  **Local Server (Recommended):** For a more robust development experience (and to avoid potential local file security restrictions in some browsers), serve the directory via a local web server.

    ```bash
    # Python 3
    python3 -m http.server
    
    # PHP
    php -S localhost:8000
    
    # Node.js (http-server)
    npx http-server
    ```

    Then navigate to `http://localhost:8000`.

### Key Implementation Details

*   **Rendering:** PDF pages are rendered onto HTML `<canvas>` elements using PDF.js.
*   **Redaction Layer:** An HTML overlay (`div.page-overlay`) is placed on top of the canvas. Redaction boxes are simple `<div>` elements with absolute positioning.
*   **Export Process:**
    1.  The application iterates through each page.
    2.  It re-renders the PDF page to a canvas (often at a higher scale for quality).
    3.  It draws black rectangles on the canvas corresponding to the user's redaction boxes.
    4.  It converts the canvas to a JPEG image (`canvas.toDataURL`).
    5.  It adds this image to a new PDF using jsPDF.
    *   *This "Canvas -> Image -> PDF" pipeline is critical for the security guarantee of the app.*