OpenXML Viewer

Minimal Chrome extension for inspecting OpenXML packages directly in the browser.

What it does

• Opens from the Chrome toolbar into a new tab
• Accepts .docx, .xlsx, .pptx, related OpenXML variants, and .zip
• Unpacks the package locally in the browser with no upload step
• Shows a file and directory tree on the left
• Shows the selected file on the right in a foldable code viewer
• Formats XML and JSON for readability
• Highlights matching brackets with rainbow colors
• Renders whitespace markers as muted middle dots
• Adds quick links for common package parts like document.xml, workbook.xml, and presentation.xml
• Supports copying the current selection or the full open file
• Falls back to a hex preview for binary parts

Stack

• React
• Vite
• Tailwind CSS
• Mantine 9
• Monaco Editor
• JSZip

Development

Install dependencies and start the app:

• npm install
• npm run dev

Build the extension

• npm run build

This produces the unpacked extension in dist.

Load in Chrome

1. Open chrome://extensions
2. Enable Developer mode
3. Click Load unpacked
4. Select the dist folder from this workspace
5. Click the extension icon to open the viewer in a new tab

Permissions

The extension requests no extra Chrome permissions.

Notes

• Everything is processed locally in the browser.
• Common OpenXML text parts are formatted automatically when opened.
• Binary files are shown as a readable hex preview instead of raw gibberish. That is a technical term. More or less.