Free Online Client-Side PDF Merger and Splitter Tool

Application Overview

A robust, high-performance web application designed for secure, local PDF manipulation. Built using React and WebAssembly via pdf-lib and pdf.js, this tool provides a native-like experience within the browser, eliminating the need to upload sensitive documents to third-party servers.

Design System & UI

• Layout: A clean, single-page application (SPA) featuring a drag-and-drop zone at the top, followed by a canvas-based grid for document management.
• Colors: Professional palette utilizing slate grays (#1e293b), white backgrounds, and high-contrast blue (#3b82f6) for call-to-action buttons.
• Animations: Subtle entry transitions for cards using framer-motion; real-time progress indicators for heavy file operations.
• Accessibility: Full keyboard support for drag-and-drop reordering and screen-reader optimized PDF metadata previews.

Key Features

PDF Merger

• Batch Processing: Merge an unlimited number of PDF files.
• Drag-and-Drop Reordering: Visually sort files before merging using a fluid grid interface.
• Conflict Handling: Automatic detection of duplicate page numbers or formatting mismatches.

PDF Splitter

• Range Selection: Extract specific page ranges (e.g., 1-5, 10-12).
• Bulk Splitting: Automatically split a multi-page PDF into single-page files.
• Delete/Extract: Select specific pages to delete or export as a new file.

Advanced Tools

• Page Rotation: Rotate individual pages 90, 180, or 270 degrees.
• Preview Engine: Real-time thumbnail generation using pdf.js to see document layout before committing changes.
• Metadata Editing: Option to strip or edit document properties (Author, Title) to ensure anonymity.
• Compression: Integrated basic compression algorithms to reduce file size for email sharing.

Technical Implementation

• Core Engine: WebAssembly-compiled libraries for high-speed binary processing.
• State Management: Zustand or Redux for managing complex arrays of file objects and page blobs.
• Storage: IndexedDB for temporary caching of large files during multi-step operations.
• Performance: Use of Web Workers to offload heavy PDF rendering and manipulation to background threads, keeping the UI responsive.