PDF Simple Editor

A lightweight, powerful, and modern PDF editor built with WinUI 3 and .NET 10. Powered by the iText 9 engine, it provides a seamless experience for editing text, managing pages, and organizing PDF documents.

🚀 Features

📝 Precision Editing

• Text Edit
  • Original Mode: After activating the Select tool, click or drag to select, double-click to edit, and Alt+Drag to move.
    • Ctrl+Enter or right-click confirms, Esc cancels.
    • If an overlap warning appears, drag to select only the overlapping fragment and edit it.
    • Single-line selections expand to the right; multi-line selections wrap to the line below.
    • Select text or drag over a region, then use the toolbar to change its font, size, color, bold, or italic. Highlighted characters in inline editing can also be styled. Changes retain the surrounding PDF content and support undo/redo.
    • If the original font is not available, a fallback font is used instead.
  • Replace Mode: After activating the Select tool, click to select and drag to move.
    • Ctrl+Enter or right-click confirms, Esc cancels.
  • Scale text: uncheck to keep the font size and reflow text when narrowing or widening its area. Check it to scale text with its area.
• Add Text: Press A to switch to the Add Text tool, then add text with custom font family, size, color, bold, and italic. Enter inserts a line break, Ctrl+Enter confirms, and Esc cancels.
• Fillable PDF forms: Click a text field or checkbox in an AcroForm PDF to enter a value. Press Enter or click away to finish a text field, then use Ctrl+S or Save As to keep the form values in the PDF. For plain PDFs without form fields, use Add Text.
• Selection & transforms: The original selection icon selects text (S). The adjacent table icon selects graphics (G): table borders, lines, shapes, images, highlights, and signatures. Click or enclose objects with a drag, Ctrl+Click to select several, and Delete to remove them.
  • Use Alt+Drag to move graphics. Drag box handles to resize text, images, and graphics; corner handles preserve proportions when scaling.
  • Drag the round handle above a selection to rotate it; hold Shift for 15-degree increments. Changes to original text and graphics support undo/redo and preserve surrounding page content.
• Images: Insert images, save a selected image as a file, or extract all embedded images to a folder.
• Region deletion (pdfSweep): Choose Tools → Region deletion or press R, then drag a rectangle to delete contents.

🖋️ Annotation & Highlighting

• Smooth Highlighting: Add semi-transparent highlights to text blocks.
• Advanced Color Control: Integrated color picker (eyedropper) and transparency sliders to customize highlight styles.
• PDF Annotations: The Annotations menu adds highlights, underlines, sticky notes and text boxes as standard PDF annotations; nearby settings control color, opacity and text-box font size.
• Annotation Management: Use Select annotations to pick annotations, then remove them with Delete or the context menu; Delete all annotations in document clears every page while keeping links, form fields and page content. Undo/redo applies.
• Annotations / Bookmarks Sidebar: The right sidebar groups annotations by page for selection, editing, deletion and sticky-note show/hide, and lists bookmarks hierarchically with hover tooltips and page navigation.
• Bookmark Editing: Use Add current page to add a bookmark and Delete to remove it with its children; changes are saved in the PDF with undo/redo.
• Signature Tool: Draw, customize, select, move, resize proportionally, edit, and save mouse-drawn signatures for reuse after reopening the PDF.
• Drawing Tools: Choose smooth Freehand, Line, Arrow, Triangle-head Arrow, Outline Arrow, Rectangle, Ellipse, or Polygon from the drawing menu. Drag to draw; for polygons, click vertices and double-click, press Enter, or click the first vertex to close. Press Esc to cancel. Set the color and stroke width beside the drawing menu. For rectangles, ellipses, and polygons, check Fill in the color settings to fill the interior with the selected color.

📂 Document Management

• Multi-Tab Interface: Work on multiple PDF files simultaneously using a modern tabbed layout.
• Page Operations: Select multiple pages with Ctrl/Shift, reorder them, delete unnecessary pages, or extract selected pages into a new PDF.
• Merge & Split: Combine multiple PDF files into one or split specific page ranges into new documents.
• Images to PDF: Select multiple PNG, JPEG, BMP, GIF, TIFF, or WebP images from Tools → Images to PDF. Each image becomes one A4 page, fitted without cropping, and the result opens in a new tab.
• PDF to Image (PNG): Right-click a page → Save page as image, or export All / Specified pages (e.g. 1,3,5-8) at 96/150/300 DPI via Tools → PDF to Image.
• Page Thumbnails: Navigate and manage pages quickly using the interactive sidebar and its right-click menu.

🛠️ Modern UX/UI

• WinUI 3 & Windows App SDK: Native look and feel with fluent design elements.
• Drag & Drop: Open files instantly by dragging them into the application.
• Text Search: Powerful search functionality to find specific phrases within the document.
• Korean / English UI: The interface is fully localized in Korean and English.
• Keyboard Shortcuts:
  • S: Switch to Text Selection
  • G: Switch to Graphic Selection
  • A: Switch to Add Text Tool
  • R: Switch to Region Deletion
  • Ctrl+O: Open File
  • Ctrl+S: Save File
  • Ctrl+F: Find Text

MCP server

Run PDFSimpleEditor.exe --mcp to start a headless server using the standard
MCP stdio transport.
The client launches the process and communicates using newline-delimited UTF-8
JSON-RPC on stdin/stdout. Normal execution still opens the editor. Closing stdin
ends the server; diagnostics use stderr only.

Open MCP → MCP settings to display and copy the standard configuration with
the current executable's absolute path. For example:

{
  "mcpServers": {
    "pdf-simple-editor": {
      "command": "C:\\Apps\\PDFSimpleEditor.exe",
      "args": ["--mcp"]
    }
  }
}

The server exposes these tools through tools/list, including argument schemas:

🛠️ Technology Stack

• Framework: .NET 10.0
• UI Framework: WinUI 3 (Windows App SDK)
• PDF Engine: iText 9.8.0 (Core, BouncyCastle), pdfSweep 5.0.8; Windows.Data.Pdf for page rendering.
• Language: C#

⚙️ Installation

📥 Download

You can download the latest version from the Releases Page.

Prerequisites

• Windows 10/11 (version 19041 or higher)
• .NET 10 SDK

Build from Source

1. Clone the repository:

   git clone https://github.com/kirinonakar/PDF_simple_edit.git
   

2. Open the solution in Visual Studio 2022 (or later).
3. Restore NuGet packages.
4. Build and run the PDF_simple_edit project.

📄 License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE file for details.