Office File Preview
Read-only preview for office documents, PDFs, diagrams, and markup files directly inside VS Code.
| Format |
Extensions |
Renderer |
| Word |
.docx |
docx-preview — text, headings, tables, lists, styles |
| Excel |
.xlsx, .xlsm |
SheetJS — all sheets with tab switcher |
| CSV |
.csv |
Lightweight table preview with UTF-8 and Shift_JIS decoding |
| PDF |
.pdf |
pdf.js — all pages, high-resolution canvas |
| PowerPoint |
.pptx |
pptx-preview — slides in list view |
| Mermaid |
.mmd, .mermaid |
Mermaid — flowcharts, sequence diagrams, Gantt, etc. |
| HTML |
.html, .htm |
Sandboxed iframe preview |
| Markdown |
.md, .markdown |
Rendered markdown with embedded Mermaid diagrams |
All previews are read-only. Files are never modified.
Usage
Opening a .docx, .xlsx, .pdf, .pptx, .mmd, or .mermaid file automatically shows the preview.
For .csv, .html, .htm, .md, and .markdown files (which have built-in VS Code editors), right-click the file → Reopen Editor With… → Office File Preview (...) to switch to the preview.
Mermaid in Markdown
Mermaid code blocks inside .md files are automatically rendered as diagrams. The theme follows VS Code's dark/light mode.
```mermaid
graph TD
A[Start] --> B{Decision}
B -->|Yes| C[Do it]
B -->|No| D[Skip]
```
Known Limitations
- pptx rendering faithfulness depends on slide complexity (animations and SmartArt may not render correctly)
- Large PDFs (200+ pages) render all pages at once; initial load may take a moment
- HTML preview uses a sandboxed iframe; resources with absolute external URLs may not load
