office-oxide-wasm — Office Documents in the Browser and Edge Runtimes

Fast Office document processing (DOCX, XLSX, PPTX, DOC, XLS, PPT) compiled to WebAssembly. Rust core, zero JavaScript runtime dependencies. Works in Node.js, bundlers (Webpack/Vite/Rollup), and modern browsers.

Part of the office_oxide toolkit. Same Rust core, same pass rate as the Rust, Python, Go, C# / .NET, and Node.js native bindings.

For Node.js without a bundler, consider the native addon (office-oxide) — it has lower overhead and doesn't require WASM init.

Quick Start

npm install office-oxide-wasm

Node.js (CommonJS or ESM)

import { readFileSync } from "node:fs";
import { WasmDocument } from "office-oxide-wasm";

const bytes = readFileSync("report.docx");
const doc = new WasmDocument(bytes, "docx");
console.log(doc.plainText());
console.log(doc.toMarkdown());
doc.free();

Bundlers (Webpack, Vite, Rollup, esbuild)

import { WasmDocument } from "office-oxide-wasm";

const response = await fetch("/report.docx");
const bytes = new Uint8Array(await response.arrayBuffer());
const doc = new WasmDocument(bytes, "docx");
console.log(doc.plainText());
doc.free();

Browser (native ES modules, no bundler)

<script type="module">
  import init, { WasmDocument } from "office-oxide-wasm/web";
  await init(); // loads the .wasm asynchronously

  const bytes = new Uint8Array(
    await (await fetch("/report.docx")).arrayBuffer()
  );
  const doc = new WasmDocument(bytes, "docx");
  document.body.textContent = doc.plainText();
  doc.free();
</script>

Why office-oxide-wasm?

• Portable — runs anywhere JavaScript runs: browsers, Node.js, Deno, Bun, Cloudflare Workers
• Reliable — 100% pass rate on valid Office files (6,062-file corpus); zero failures on legitimate documents
• Complete — 6 formats: DOCX, XLSX, PPTX + legacy DOC, XLS, PPT
• Permissive — MIT / Apache-2.0, no AGPL or GPL restrictions
• No native build — pure WASM bundle, works without node-gyp or a C compiler

API

WasmDocument is the single entry point.

| Method | Description | | --- | --- | | new WasmDocument(bytes, format) | Open from Uint8Array. format: "docx" \| "xlsx" \| "pptx" \| "doc" \| "xls" \| "ppt". | | .formatName() | Detected format as a string. | | .plainText() | Extract plain text. | | .toMarkdown() | Convert to Markdown. | | .toHtml() | Convert to an HTML fragment. | | .toIr() | Return the format-agnostic document IR (JS object). | | .free() | Release the underlying WASM memory. [Symbol.dispose] is also supported. |

TypeScript definitions are shipped.

Package Layout

office-oxide-wasm exports three targets via the exports map:

| Subpath | Target | Use when | | --- | --- | --- | | office-oxide-wasm | bundler (ESM) | Default for bundlers; Node picks CJS automatically | | office-oxide-wasm/node | Node CommonJS | Pure Node without a bundler | | office-oxide-wasm/web | browser ESM | Direct <script type="module"> in the browser | | office-oxide-wasm/bundler | bundler ESM | Explicit bundler entry |

Other languages

office_oxide ships the same Rust core through six bindings:

• Rust — cargo add office_oxide — see docs.rs/office_oxide
• Python — pip install office-oxide — see python/README.md
• Go — go get github.com/yfedoseev/office_oxide/go — see go/README.md
• JavaScript (native, no WASM) — npm install office-oxide — see js/README.md
• C# / .NET — dotnet add package OfficeOxide — see csharp/OfficeOxide/README.md

Why I built this

I needed Office document processing that works in the browser without a server round-trip — and without pulling in a JVM or a GPL-licensed dependency. The same Rust core that powers the CLI and all native bindings compiles cleanly to WASM, so feature parity is automatic.

If something's broken or missing, open an issue.

— Yury

License

MIT OR Apache-2.0

WASM + Rust core | MIT / Apache-2.0 | 100% pass rate on valid Office files (6,062-file corpus) | Browser + Node.js + edge runtimes | 6 formats