Modern PDF Preview is a next-generation PDF viewer for VS Code, designed for speed, accuracy, and productivity.

It is built on top of PDFium WASM and wrapped with embed-pdf-viewer, delivering a Chrome-grade rendering experience directly inside your editor.

Powered by WebAssembly (WASM), this extension renders large PDFs instantly without slowing down VS Code. Smooth scrolling and zooming come standard.

Review and mark up documents directly.

• Highlight important text.
• Draw ink signatures or diagrams.
• Add Notes and comments.
• Direct Save: Press Ctrl+S (Windows/Linux) or Cmd+S (macOS) to directly overwrite the PDF file with your modifications.

Works everywhere you use VS Code.

• Desktop: Full features supported on Windows, macOS, and Linux.
• Web: Supports VS Code for Web (vscode.dev) and GitHub Codespaces.
  • Note: The Web version is optimized for viewing only. Other features (like annotation saving) are not guaranteed to work in the browser environment.
• Privacy-First: All rendering happens locally. Your data never leaves your machine (or browser sandbox).

Customize the initial viewer state in your VS Code settings:

• modernPdfViewer.defaultZoomLevel: Initial zoom (e.g., page-width, page-fit, 100%).
• modernPdfViewer.defaultSpreadMode: Initial spread (e.g., none, odd, even).

• Theme Sync: Automatically adapts to Light, Dark, and High Contrast themes.
• Rich Toolbar: Thumbnails, Outline/Bookmarks, Search, Print, and Presentation Mode.

• Multiple Webviews: Each PDF document opens in its own independent Webview container.
• No Automatic Recycling: The extension does not implement an automatic LRU (Least Recently Used) recycling mechanism for open documents.
• Memory Usage: To ensure high performance and context retention (retainContextWhenHidden: true), Webviews are kept in memory even when hidden.
• Recommendation: Please manually close PDF tabs you are no longer using to free up system resources, especially when dealing with very large files.

Search for "Modern PDF Preview" in the VS Code Extensions panel or use the ID: chocolatedesue.modern-pdf-preview.

• Technical Architecture: How WASM and Web Workers are used.
• Development Guide: Setup, build, testing, and release procedures.
• API Reference: Preview PDFs from your own extension.
• Troubleshooting: Solutions for common issues.

This project is an evolution of vscode-pdf-viewer and uses:

• embed-pdf-viewer: Core UI component.
• PDFium WASM: High-performance rendering engine (Apache 2.0 / BSD 3-Clause).

License: MIT