Rust-native OOXML engines with collaboration and agent editing at the core.
WebAssembly for browsers. Headless APIs for servers. Native Rust where you need it.

• Documents, spreadsheets, and slides. Open, edit, render, and save DOCX, XLSX and PPTX files with high fidelity. Native OOXML editing preserves untouched file parts losslessly when round-tripping.

• Agent editing with human review. Review attributed agent edits through tracked changes, inline diffs, and before-and-after previews. Accept or reject DOCX proposals in the optional proposal sidebar.

• Real-time collaboration. People and agents edit the same file together, with live cursors and selections. Concurrent changes merge automatically, and offline edits sync when peers reconnect.

• Undo and redo. Navigate editing history and undo accepted agent proposals as a single step.

• Embed or automate. Drop React editors into your app, build on the framework-free JavaScript cores, or use Rust and Python APIs for headless processing and agent workflows.

• Open source and self-hostable. Apache-2.0 licensed, with control over your document storage, deployment, and collaboration infrastructure.

Try it out, or explore the docs for setup, APIs, and format support.

Rust: typed engine API. Core: @betteroffice/<format>, the framework-free core through WebAssembly. Core (native): the same engine as prebuilt native bindings for Node.js, Bun and Deno on macOS, Linux and Windows. React: drop-in editor. Python: read, edit, render, save.

More packages:

• Agent tools: @betteroffice/agents, the TypeScript SDK and betteroffice-mcp server.
• Fonts: @betteroffice/fonts, @betteroffice/fonts-cjk, @betteroffice/fonts-intl, @betteroffice/fonts-latin.
• i18n: @betteroffice/docx-i18n, @betteroffice/xlsx-i18n, @betteroffice/pptx-i18n.

What to install for which language, with a first example each: npm, crates.io, PyPI.

Upgrading from 0.4? See Migrating to 0.5.

Layout needs the fonts a document names. BetterOffice ships open substitutes with the same advance widths as the Microsoft core fonts (Carlito for Calibri, Caladea for Cambria, Liberation Sans, Serif and Mono for Arial, Times New Roman and Courier New) plus script coverage, so line breaks and pagination match Office without the original fonts installed. DOCX layout resolves a face in this order: fonts embedded in the document, fonts your app configures, the bundled packs, then a last resort fallback.

Node.js, Bun and Deno. @betteroffice/docx and @betteroffice/pptx depend on the font manager @betteroffice/fonts, which installs fonts-latin. Add fonts-intl or fonts-cjk to cover those scripts. DOCX reads each face from the installed package files the first time a document needs it; nothing is downloaded. Reading package files needs Node.js 20.16 or 22.3 and later, Bun or Deno.

Native bindings, Rust and Python. The Rust format crates bundle all three packs by default and resolve faces in the same order, with nothing fetched; see the Rust guide to leave packs out or load them from your own location. @betteroffice/pptx-native installs the npm packs and reads each face from disk; @betteroffice/docx-native uses the same font manager as @betteroffice/docx. For Python, register the faces a document needs before rendering.

Generated by the Benchmarks action; per-document results are on the benchmarks site.

For how scores, timings and coverage are measured, see the benchmark methodology.

Model: gpt-6-luna, Harness: codex, three runs per task, on the v3 format eval suite: 96 basic and 33 complex editing tasks on pinned public real-world documents. A run passes only if the requested edit is correct, the rest of the file is untouched, and the input is unchanged.

Per-task results and methodology.

• crates/: the Rust engines
• packages/: the TypeScript editor packages
• bindings/: the Python bindings
• e2e/: browser tests, corpus scenarios, and the shared test harness
• apps/web: betteroffice.dev (Next.js on Cloudflare Workers)
• apps/demo: editor playground
• apps/docs: documentation

bun install
bun run dev:demo     # editor playground; builds the wasm bundles on first run
bun run dev          # betteroffice.dev site (no wasm needed)
bun run dev:docs     # documentation site
bun run rust:check   # fmt + clippy + tests for the engines

Run bun run test:e2e:browser for headless browser tests of all three editors. The E2E guide also covers pinned corpus scenarios, cross-SDK checks, and operation profiles.

Use the Office visual quality harness to export Word, PowerPoint, and Excel references, compare local renders, or refresh the fidelity scores with the manual action.

Contributions are welcome. We ask for a one-time signature of the Contributor License Agreement on your first pull request (corporate version).

Apache-2.0. Third-party attribution in THIRD-PARTY-NOTICES.md.