offline-doc-preview

Two React components (a full-pane reader and a thumbnail tile) that render PDF, Word, Excel, PowerPoint, images, HTML, video, audio, Markdown, JSON, XML, CSV and plain text entirely in the browser, with no external services of any kind. Nothing is uploaded, nothing is converted server-side, and no Office Online / Google Docs viewer is embedded behind the scenes. It works behind a firewall or on an air-gapped machine.

Install

npm install offline-doc-preview

This package doesn't bundle its own copy of React so your app needs to already have React 18 or 19 installed (react and react-dom are listed as peerDependencies, so npm won't install them for you automatically).

The code for each format (PDF, Excel, etc.) is split into its own chunk and only loaded from your app's own bundle the first time that format is actually previewed. This is the same lazy-loading any code-split app already does, not a network call anywhere else. If your app only ever previews Markdown files, the PDF and spreadsheet chunks never get loaded at all.

Usage

import { DocumentPreview } from 'offline-doc-preview'
import 'offline-doc-preview/styles.css'
import workerSrc from 'pdfjs-dist/build/pdf.worker.min.mjs?url'

<DocumentPreview
  url="/files/report.docx"
  mimeType="application/vnd.openxmlformats-officedocument.wordprocessingml.document"
  pdf={{ workerSrc }}
/>

For a file listing, DocumentThumbnail takes the same inputs and renders a single representative frame for page 1, slide 1, or the top-left of the first sheet:

import { DocumentThumbnail } from 'offline-doc-preview'

<DocumentThumbnail url="/files/report.docx" fit="cover" pdf={{ workerSrc }} />

The PDF renderer needs a worker and won't guess where one lives, so pass pdf={{ workerSrc }} as shown above (see the main repo README for CJK font and search setup notes).

Formats

| Format | Extensions | | ------ | ---------- | | PDF | .pdf | | Word | .docx | | Excel | .xlsx | | PowerPoint | .pptx | | Images | .png .jpg .jpeg .jfif .gif .webp .avif .bmp .ico .svg | | TIFF | .tif .tiff (Safari only) | | Markdown | .md .markdown .mdown .mkd | | JSON | .json .jsonc .jsonl .ndjson | | XML | .xml .xsd .xsl .xslt .rss .atom | | HTML | .html .htm | | Video | .mp4 .webm .mov .ogv | | Audio | .mp3 .wav .m4a .oga .ogg | | CSV / TSV | .csv .tsv | | Text | .txt .text .log .yaml .yml |

Anything else, including legacy .doc, .xls and .ppt, renders a clear "unsupported format" state with a download link rather than failing.

Links

• Full documentation, PDF setup, search, and theming
• Issues

License

MIT