oxidocs

A Word-compatible .docx layout and rendering engine, compiled to WebAssembly — parse, lay out, edit and PDF-export Microsoft Word documents entirely in the browser (or any JS runtime).

Early development. The API is 0.x and unstable; development happens in the open at https://gitlab.com/Ryujiyasu/oxi. The engine core is also published on crates.io as oxidocs.

What it does

• Parses OOXML WordprocessingML (.docx) into a structured document model
• Lays out documents with a line/page model measured against Microsoft Word's own rendering — including Japanese typography: kinsoku line breaking, document grid (docGrid), ruby, vertical writing
• Edits text with incremental re-layout, and exports to PDF (embedded CJK fonts included)

How fidelity is measured

Layout is verified continuously against Word as the oracle: per-paragraph pagination equality (100% on the current 87-document corpus of real-world Japanese government/legal documents) and per-page SSIM pixel comparison.

Usage

import init, { parse_document, layout_document, docx_to_pdf } from 'oxidocs';

await init();
const bytes = new Uint8Array(await file.arrayBuffer());
const doc = parse_document(bytes);      // structured document model
const pages = layout_document(bytes);   // laid-out pages (positions in pt)
const pdf = docx_to_pdf(bytes);         // Uint8Array (PDF)

License

MIT OR Apache-2.0 (bindings). The engine core is MPL-2.0.