Office Oxide — The Fastest Native Office Document Library

A fast, memory-safe library for text extraction from Office documents. Rust core with first-class bindings for Python, Go, C#/.NET, Node.js (native and WASM), and a stable C FFI. Handles DOCX, XLSX, PPTX, DOC, XLS, and PPT. Up to 100× faster than python-docx, openpyxl, python-pptx, and xlrd. Beats python-calamine on XLSX. 100% pass rate on valid Office files — zero failures on legitimate Word/Excel/PowerPoint documents. MIT/Apache-2.0 dual-licensed.

Scope of "fastest". Benchmarks compare Office Oxide against other native / embeddable libraries (no JVM runtime required): python-docx, openpyxl, python-pptx, python-calamine, xlrd, markitdown, catdoc, antiword, xls2csv, calamine (Rust), dotext, docx-rs. Apache POI and Apache Tika are out of scope for this comparison because they require a JVM and are targeted at a different deployment shape. POI/Tika numbers may be added in a future release.

Available bindings

Language	Package	Directory	Docs
Rust	office_oxide on crates.io	src/	lib.rs
Python	office-oxide on PyPI	python/	python/
Go	github.com/yfedoseev/office_oxide/go	go/	go/README.md
C# / .NET	OfficeOxide on NuGet	csharp/	csharp/OfficeOxide/README.md
Node.js (native)	office-oxide on npm	js/	js/README.md
Node.js / browser (WASM)	office-oxide-wasm on npm	wasm-pkg/	wasm-pkg/README.md
C / other	header-only via FFI	include/office_oxide_c/	office_oxide.h
CLI	office-oxide binary	crates/office_oxide_cli/
MCP server	office-oxide-mcp binary	crates/office_oxide_mcp/

Ready-to-run demos (extract, replace, read_xlsx) exist for every binding under examples/. Deeper language-specific guides live in docs/: Rust · Python · Go · C# · JavaScript (native) · WASM · C FFI.

Quick Start

Python

from office_oxide import Document, extract_text, to_markdown

# One-liner text extraction
text = extract_text("report.docx")
markdown = to_markdown("data.xlsx")

# Context-managed document; accepts str or pathlib.Path
with Document.open("slides.pptx") as doc:
    print(doc.format)       # "pptx"
    print(doc.plain_text())
    print(doc.to_markdown())

pip install office-oxide

Rust

use office_oxide::Document;

let doc = Document::open("report.docx")?;
let text = doc.plain_text();
let markdown = doc.to_markdown();
let ir = doc.to_ir(); // Format-agnostic intermediate representation

[dependencies]
office_oxide = "0.1.1"

JavaScript / WASM

Browser + bundlers:

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

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

Node.js native (koffi + C FFI, no node-gyp):

import { Document } from "office-oxide";

using doc = Document.open("report.docx");
console.log(doc.format);          // "docx"
console.log(doc.plainText());
console.log(doc.toMarkdown());
console.log(doc.toIr());

npm install office-oxide         # native addon
npm install office-oxide-wasm    # portable WASM

Go

import oo "github.com/yfedoseev/office_oxide/go"

doc, _ := oo.Open("report.docx")
defer doc.Close()
text, _ := doc.PlainText()
md,   _ := doc.ToMarkdown()

C# / .NET

using OfficeOxide;

using var doc = Document.Open("report.docx");
Console.WriteLine(doc.Format);        // "docx"
Console.WriteLine(doc.PlainText());
Console.WriteLine(doc.ToMarkdown());

C (raw FFI)

Include include/office_oxide_c/office_oxide.h and link against liboffice_oxide. See examples/c/extract.c for a working sample.

Why office_oxide?

• Fast — 8-100× faster than python-docx, openpyxl, python-pptx, xlrd; beats calamine on XLSX
• Reliable — 100% pass rate on valid Office files, tested against 6,062 real-world documents. Zero failures on legitimate Word 97+ / Excel 97+ / PowerPoint 97+ files
• Complete — 6 formats: DOCX, XLSX, PPTX + legacy DOC, XLS, PPT
• Multi-platform — Rust, Python, Go, JavaScript/TypeScript, C#/.NET, WASM, CLI, and MCP server — one library, all platforms
• Permissive — MIT / Apache-2.0, no AGPL or GPL restrictions

Performance

Benchmarked on 6,062 files from 11 independent public test suites. Single-thread, release build with LTO, warm disk cache (steady-state), median of three runs on an idle system. Full methodology in BENCHMARKS.md.

DOCX — 2,538 files

Library	Language	Mean	p99	Pass Rate	License
office_oxide	Rust	0.8ms	3.9ms	98.9%	MIT
python-docx	Python	11.8ms	98ms	95.1%	MIT

XLSX — 1,802 files

Library	Language	Mean	p99	Pass Rate	License
office_oxide	Rust	5.0ms	40ms	97.8%	MIT
python-calamine	Rust/Python	13.9ms	183ms	96.6%	MIT
openpyxl	Python	94.5ms	698ms	96.2%	MIT

PPTX — 806 files

Library	Language	Mean	p99	Pass Rate	License
office_oxide	Rust	0.7ms	3.9ms	98.4%	MIT
python-pptx	Python	32.5ms	174ms	86.7%	MIT

Legacy Formats — 916 files

Library	Format	Mean	p99	Pass Rate	License
office_oxide	DOC (246)	0.3ms	3.4ms	94.7%	MIT
catdoc	DOC	4.3ms	41ms	90.2%	GPL-2.0
antiword	DOC	4.5ms	66ms	76.8%	GPL-2.0
office_oxide	XLS (494)	2.8ms	75ms	99.2%	MIT
xls2csv (catdoc)	XLS	6.9ms	58ms	84.0%	GPL-2.0
python-calamine	XLS	9.0ms	96ms	90.7%	MIT
xlrd	XLS	36.6ms	503ms	93.1%	BSD-3
office_oxide	PPT (176)	0.7ms	6.6ms	100%	MIT
catppt (catdoc)	PPT	2.8ms	8ms	77.8%	GPL-2.0

On .xls, xls2csv has a tighter p99 (58ms vs 75ms) because it emits truncated/lossy output on complex sheets. office_oxide is 2.4× faster on the mean and passes 15pp more of the corpus. No other Rust or Python library supports .doc, .xls, and .ppt text extraction without a JVM (Apache Tika) or external binaries.

Corpus

Source	Files	License
LibreOffice Core	2,185	MPL-2.0
Apache POI	1,298	Apache-2.0
Open XML SDK	707	MIT
ClosedXML	371	MIT
Pandoc	224	GPL-2.0
python-docx + python-pptx	111	MIT
Apache Tika	108	Apache-2.0
calamine	28	MIT
openpreserve	20	CC0
oletools	17	BSD-2
LibreOffice (legacy)	12	MPL-2.0
Total	6,062

Pass Rate — 100% on valid files

100% pass rate on all valid Office files — the 97 non-passing files in the corpus are all invalid inputs:

Category	Count	Notes
Truncated / corrupted ZIP	43	Missing EOCD, invalid Central Directory, fuzzer-corrupted archives
Encrypted / password-protected	19	CFBF-encrypted containers — no password supplied
XML bomb / security fixture	17	Billion-laughs entities, CVE exploit inputs, fuzzer corpus
Wrong format / mislabeled	16	WordPerfect, IBM DisplayWrite, pre-OLE2 Excel 3/4, ODT stored as .docx, XLSB stored as .xls
Truncated binary	2	File ends mid-CFB-sector

Zero failures on legitimate Word 97+ / Excel 97+ / PowerPoint 97+ files. Zero panics, zero timeouts, zero false negatives on valid documents. Full breakdown in BENCHMARKS.md.

Supported Formats

Format	Extension	Read	Write	Edit	Convert	Text	Markdown	HTML	IR
Word (OOXML)	.docx	Yes	Yes	Yes	—	Yes	Yes	Yes	Yes
Excel (OOXML)	.xlsx	Yes	Yes	Yes	—	Yes	Yes	Yes	Yes
PowerPoint (OOXML)	.pptx	Yes	Yes	Yes	—	Yes	Yes	Yes	Yes
Word (Legacy)	.doc	Yes	—	—	→ .docx	Yes	Yes	Yes	Yes
Excel (Legacy)	.xls	Yes	—	—	→ .xlsx	Yes	Yes	Yes	Yes
PowerPoint (Legacy)	.ppt	Yes	—	—	→ .pptx	Yes	Yes	Yes	Yes

Legacy formats can be converted to modern OOXML with save_as():

doc = Document.open("report.doc")
doc.save_as("report.docx")  # Converts DOC → DOCX

Python API

from office_oxide import Document, extract_text, to_markdown, to_html

# Quick extraction
text = extract_text("report.docx")
markdown = to_markdown("spreadsheet.xlsx")
html = to_html("slides.pptx")

# Document object
doc = Document.open("presentation.pptx")
text = doc.plain_text()
md = doc.to_markdown()
html = doc.to_html()
ir = doc.to_ir()  # Structured JSON intermediate representation
fmt = doc.format_name()  # "pptx"

# From bytes
with open("file.docx", "rb") as f:
    doc = Document.from_bytes(f.read(), "docx")

All 6 formats supported. Works with str, pathlib.Path, or raw bytes.

Rust API

use office_oxide::{Document, DocumentFormat};

// Open from path (format auto-detected from extension)
let doc = Document::open("report.docx")?;

// Open from reader with explicit format
let file = std::fs::File::open("data.xlsx")?;
let doc = Document::from_reader(file, DocumentFormat::Xlsx)?;

// Extract content
let text = doc.plain_text();
let markdown = doc.to_markdown();
let html = doc.to_html();
let ir = doc.to_ir(); // Format-agnostic DocumentIR

// Access format-specific types
if let Some(docx) = doc.as_docx() {
    println!("Paragraphs: {}", docx.body.elements.len());
}

// Create documents from IR
use office_oxide::create::create_from_ir;
create_from_ir(&ir, DocumentFormat::Docx, "output.docx")?;

Sub-modules

Each format is available as a sub-module for direct access:

use office_oxide::docx::DocxDocument;
use office_oxide::xlsx::XlsxDocument;
use office_oxide::pptx::PptxDocument;
use office_oxide::doc::DocDocument;
use office_oxide::xls::XlsDocument;
use office_oxide::ppt::PptDocument;

Installation

Python

pip install office-oxide

Wheels available for Linux, macOS, and Windows. Python 3.8–3.14.

Rust

[dependencies]
office_oxide = "0.1.1"

JavaScript/WASM

npm install office-oxide-wasm    # portable WASM (browser + Node.js)
npm install office-oxide         # native addon via koffi (Node.js only, no node-gyp)

Go

go get github.com/yfedoseev/office_oxide/go

See go/README.md for setup details.

C# / .NET

dotnet add package OfficeOxide

See csharp/OfficeOxide/README.md for setup details.

CLI

cargo install office_oxide_cli       # Cargo
cargo binstall office_oxide_cli      # Pre-built binary

MCP Server

cargo install office_oxide_mcp

CLI

office-oxide provides fast Office document processing from your terminal:

office-oxide text report.docx         # Extract plain text
office-oxide markdown data.xlsx       # Convert to Markdown
office-oxide html slides.pptx         # Convert to HTML
office-oxide ir document.docx         # Dump IR as JSON
office-oxide info report.docx         # Show format and metadata

All six formats supported (docx, xlsx, pptx, doc, xls, ppt). Use --help for all options.

MCP Server

office-oxide-mcp lets AI assistants (Claude, Cursor, etc.) read Office documents locally via the Model Context Protocol.

Add to your MCP client configuration:

{
  "mcpServers": {
    "office-oxide": { "command": "office-oxide-mcp" }
  }
}

The server exposes extract and info tools. All processing runs locally — no files leave your machine.

Building from Source

git clone https://github.com/yfedoseev/office_oxide
cd office_oxide
cargo build --release
cargo test

# Python bindings
maturin develop --features python

# Shared library for Go, JS/TS (koffi), and C# bindings
cargo build --release --lib
# Output: target/release/liboffice_oxide.{so,dylib} or office_oxide.dll

Documentation

• Documentation Site — Guides and examples
• Getting Started (Rust) — Rust guide
• Getting Started (Python) — Python guide
• Getting Started (Go) — Go guide
• Getting Started (JavaScript / TypeScript) — Node.js native guide
• Getting Started (WASM) — Browser and Node.js WASM guide
• Getting Started (C# / .NET) — .NET guide
• Getting Started (C FFI) — C FFI guide
• API Docs (Rust) — Full Rust API reference
• Architecture — System design and module structure

Use Cases

• RAG / LLM pipelines — Extract clean text or Markdown from Office documents for retrieval-augmented generation
• Document processing at scale — Parse thousands of documents in seconds
• Data extraction — Pull structured data from spreadsheets, tables, and presentations
• Format conversion — Convert between formats via the intermediate representation
• python-docx / openpyxl alternative — Up to 100× faster, supports all 6 formats in one library

Why I built this

I needed a library that could read all six Office formats at once — not six separate packages — and I needed it without pulling in a JVM, a Python runtime, or a GPL-licensed dependency. Nothing existed that combined speed, correctness, and a permissive license across the full DOCX / XLSX / PPTX / DOC / XLS / PPT surface, so I wrote it in Rust and wrapped it for every language I use day-to-day. The same binary powers Python via PyO3, Node.js via koffi, Go via cgo, C# via P/Invoke, and the browser via WASM — one fix lands everywhere.

If it saves you a dependency, a license audit, or a weekend, consider leaving a star. If something's broken or missing, open an issue — I read all of them.

— Yury

License

Dual-licensed under MIT or Apache-2.0 at your option. No AGPL, no GPL, no copyleft restrictions. Use freely in commercial and open-source projects.

Contributing

We welcome contributions! See CONTRIBUTING.md for guidelines.

cargo build && cargo test && cargo fmt && cargo clippy -- -D warnings

Citation

@software{office_oxide,
  title = {Office Oxide: Fast Office Document Processing for Rust, Python, Go, JavaScript, and C#},
  author = {Yury Fedoseev},
  year = {2026},
  url = {https://github.com/yfedoseev/office_oxide}
}

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Rust + Python + Go + JS/TS + C# + WASM + CLI + MCP | MIT/Apache-2.0 | 100% pass rate on valid Office files (6,062-file corpus) | Up to 100× faster than alternatives | 6 formats