OpenXML Viewer

A Visual Studio Code extension that lets you preview Office Open XML files (.xlsx / .docx / .pptx) directly inside Visual Studio Code. Just double-click a file to quickly inspect its contents—without launching Excel, Word, or PowerPoint.

[!NOTE] This extension is intended for viewing (read-only). It does not provide editing or saving capabilities.

Table of Contents

• OpenXML Viewer
  • Table of Contents
  • Key Features
  • Supported File Formats
  • Requirements
  • Installation
    • From the Visual Studio Code Marketplace
    • From a VSIX File
  • Usage
  • Commands
  • Settings
  • Limitations
  • Roadmap
  • Contributing
  • Sponsors
  • License

Key Features

• 📊 View Excel workbooks (.xlsx)
  • Display cell contents in a table, sheet by sheet
  • Switch between multiple sheets with tabs
  • Resize column widths and row heights (drag borders, double-click to auto-fit, reset per sheet); adjustments persist across reopen
• 📝 View Word documents (.docx)
  • Display body structure such as paragraphs, headings, and tables
• 📑 View PowerPoint presentations (.pptx)
  • Display text, shapes, and images for each slide
  • Jump from the slide list (thumbnails)
• 🔍 In-viewer text search
  • Run a full-text search over the displayed content and highlight matches
  • Jump to the previous/next match (moving across sheets and slides)
• 🖱️ Seamless operation
  • Launch the preview simply by opening a file in the Explorer (custom editor)
  • No need to launch external applications
• 🔒 Safe viewing
  • Read-only, so accidental edits cannot corrupt the file
  • The Webview's Content Security Policy (CSP) restricts loading external resources

Supported File Formats

[!IMPORTANT] The target is Office Open XML (OOXML) files. Legacy binary formats (.xls / .doc / .ppt) and macro-enabled formats (such as .xlsm) are not supported.

Requirements

• Visual Studio Code 1.90.0 or later
• No additional runtime or external application (such as Microsoft Office) is required

Installation

From the Visual Studio Code Marketplace

1. Open the Extensions view from the VS Code sidebar (Ctrl+Shift+X / ⌘+Shift+X)
2. Search for OpenXML Viewer
3. Click Install

From a VSIX File

code --install-extension openxml-viewer-<version>.vsix

Alternatively, open the Command Palette (Ctrl+Shift+P / ⌘+Shift+P), run "Extensions: Install from VSIX...", and select the .vsix file.

Usage

1. Open a .xlsx / .docx / .pptx file in the VS Code Explorer.
2. This extension's custom editor launches automatically and shows a preview of the contents.
3. If you want to open the file in the default text editor or another editor, right-click the file and switch the way it opens via "Open With...".

[!TIP] If you want to change the default way a file opens, you can set the default editor per extension via "Open With..." → "Configure default editor for '*.xlsx'...".

Type a keyword into the search bar at the top of the preview to run a full-text search over the displayed document. Press Enter / Shift+Enter to move to the next / previous match, and Esc to clear the search. For spreadsheets and presentations, the viewer automatically switches to the matching sheet / slide.

Commands

These are available from the Command Palette (Ctrl+Shift+P / ⌘+Shift+P).

Settings

You can configure these in settings.json (user settings / workspace settings).

Example configuration:

{
  "openxmlViewer.spreadsheet.maxRows": 5000,
  "openxmlViewer.theme": "dark"
}

Limitations

[!WARNING] This extension is intended to provide a simple preview. It does not guarantee rendering that is fully compatible with Excel, Word, or PowerPoint. The layout, formatting, colors, and so on may differ from how the file appears in the original Office application.

• Editing, saving, and printing are not supported (view-only).
• Complex layouts (advanced shapes, SmartArt, charts, conditional formatting, macros, and so on) may be simplified or hidden.
• Password-protected or encrypted files cannot be opened.
• Formulas display their cached result values (no recalculation is performed).
• Legacy binary formats (.xls / .doc / .ppt) are not supported.

Roadmap

• [x] .xlsx viewer (cells, multiple sheets)
• [x] .docx viewer (body, tables, images)
• [x] .pptx viewer (slides, thumbnails)
• [x] In-viewer text search (match highlighting, previous/next navigation)
• [x] Resizable spreadsheet column widths and row heights (drag, auto-fit, persistence)
• [ ] Text copy support
• [ ] Enhanced chart and shape rendering
• [ ] Export (PDF / HTML)

Contributing

Bug reports, feature requests, and pull requests are welcome. Feel free to reach out via Issues.

For specifications, design, and build/debug instructions, see DEVELOPMENT.md. For publishing to the Marketplace, see PUBLISHING.md.

Sponsors

If you would like to support the development of this project, contributions via GitHub Sponsors are welcome. Your support will be used to improve features and maintain the project over time.

License

This project is released under the MIT License.