Project

kreuzberg

2.01
The project is in a healthy, maintained state
Kreuzberg is a high-performance document intelligence library with a Rust core and native Ruby bindings via Magnus. Extract text, metadata, and structured data from 75+ file formats including PDF, DOCX, PPTX, XLSX, HTML, RTF, images (with OCR), email, archives, and more. Features async/sync APIs, text chunking, language detection, and keyword extraction.
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 Dependencies

Development

~> 4.0
~> 13.0
~> 3.12
~> 0.9
~> 1.66
~> 4.0
~> 2.0

Runtime

~> 0.9.119
 Project Readme

Kreuzberg

Extract text, metadata, and code intelligence from 90+ file formats and 300+ programming languages at native speeds without needing a GPU.

Key Features

  • Code intelligence – Extract functions, classes, imports, symbols, and docstrings from 300+ programming languages via tree-sitter. Results in ExtractionResult.code_intelligence with semantic chunking
  • Extensible architecture – Plugin system for custom OCR backends, validators, post-processors, document extractors, and renderers
  • Polyglot – Native bindings for Rust, Python, TypeScript/Node.js, Ruby, Go, Java, Kotlin, C#, PHP, Elixir, R, Dart, Swift, Zig, and C
  • 90+ file formats – PDF, Office documents, images, HTML, XML, emails, archives, academic formats across 8 categories
  • LLM intelligence – VLM OCR (GPT-4o, Claude, Gemini, Ollama), structured JSON extraction with schema constraints, and provider-hosted embeddings via 143 LLM providers (including local engines: Ollama, LM Studio, vLLM, llama.cpp) through liter-llm
  • OCR support – Tesseract (all bindings, including Tesseract-WASM for browsers), PaddleOCR (all native bindings), EasyOCR (Python), VLM OCR (143 vision model providers including local engines), extensible via plugin API
  • High performance – Rust core with pure-Rust PDF, SIMD optimizations and full parallelism
  • Flexible deployment – Use as library, CLI tool, REST API server, or MCP server
  • TOON wire format – Token-efficient serialization for LLM/RAG pipelines, ~30-50% fewer tokens than JSON
  • GFM-quality output – Comrak-based rendering with proper fenced code blocks, table nodes, bracket escaping, and cross-format parity (Markdown, HTML, Djot, Plain)
  • HTML passthrough – HTML-to-Markdown conversion uses html-to-markdown output directly, bypassing lossy intermediate round-trips
  • Memory efficient – Streaming parsers for multi-GB files

Complete Documentation | Live Demo | Installation Guides

Installation

Each language binding provides comprehensive documentation with examples and best practices. Choose your platform to get started:

Scripting Languages:

  • Python – PyPI package, async/sync APIs, OCR backends (Tesseract, PaddleOCR, EasyOCR)
  • Ruby – RubyGems package, idiomatic Ruby API, native bindings
  • PHP – Composer package, modern PHP 8.2+ support, type-safe API, async extraction
  • Elixir – Hex package, OTP integration, concurrent processing
  • R – r-universe package, idiomatic R API, extendr bindings
  • Dart / Flutter – pub.dev package, flutter_rust_bridge runtime, native bindings for macOS/iOS/Android/Linux/Windows

JavaScript/TypeScript:

  • @kreuzberg/node – Native NAPI-RS bindings for Node.js/Bun, fastest performance
  • @kreuzberg/wasm – WebAssembly for browsers/Deno/Cloudflare Workers, comprehensive format and OCR support (PDF, Excel, archives, all office formats, real Tesseract via the WASI build) — only ORT-dependent features (paddle-ocr, layout detection, embeddings, auto-rotate) and server modes (api/mcp/cli) are excluded

Compiled Languages:

  • Go – Go module with FFI bindings, context-aware async
  • Java – Maven Central, Foreign Function & Memory API
  • Kotlin – Maven Central, Kotlin/JVM with idiomatic data classes, sealed enums, and coroutine-based async
  • C# – NuGet package, .NET 6.0+, full async/await support
  • Swift – Swift Package Manager, macOS 13+/iOS 16+, native Swift types and async/await

Native:

  • Rust – Core library, flexible feature flags, zero-copy APIs
  • Zigzig fetch + build.zig.zon, idiomatic error sets, optional types, slice-based memory
  • C (FFI) – C header + shared library, pkg-config/CMake support, cross-platform

Containers:

  • Docker – Official images with API, CLI, and MCP server modes (Core: ~1.0-1.3GB, Full: ~1.0-1.3GB with OCR + legacy format support)

Command-Line:

  • CLI – Cross-platform binary, batch processing, MCP server mode

All language bindings include precompiled binaries for both x86_64 and aarch64 architectures on Linux and macOS.

Platform Support

Complete architecture coverage across all language bindings:

Language Linux x86_64 Linux aarch64 macOS ARM64 Windows x64
Python
Node.js
WASM
Ruby -
R
Elixir
Go
Java
Kotlin
C#
PHP
Swift - - -
Dart
Zig
Rust
C (FFI)
CLI
Docker -

Note: ✅ = Precompiled binaries available with instant installation. WASM runs in any environment with WebAssembly support (browsers, Deno, Bun, Cloudflare Workers). All platforms are tested in CI. MacOS support is Apple Silicon only.

Mobile (iOS, Android)

Target ORT-dependent features*
iOS (aarch64-apple-ios, aarch64-apple-ios-sim)
Android arm64 (aarch64-linux-android)
Android x86_64 emulator (x86_64-linux-android)

*ORT-dependent features: PaddleOCR, layout detection, embeddings, auto-rotate. All non-ORT capabilities (Tesseract OCR, every document format, chunking, language detection, keywords, tree-sitter code intelligence, API/MCP, LLM) are available on all four mobile targets.

The x86_64-linux-android emulator triple lacks an ORT prebuilt upstream; kreuzberg's kreuzberg crate exposes an android-target aggregate feature that selects the same no-ORT feature set as WASM. The kreuzberg-ffi and kreuzberg-dart crates auto-select that aggregate for the emulator via target-conditional dependencies — host and arm64 phones get full features automatically.

Browsers / Edge (WebAssembly)

WASM excludes the same ORT-dependent feature set as the Android x86_64 emulator. The shared no-ORT base lives behind the no-ort-target feature in the core crate; both wasm-target and android-target compose it.

Embeddings Support (Optional)

To use embeddings functionality:

  1. Install ONNX Runtime 1.24+:

  2. Use embeddings in your code - see Embeddings Guide

Note: Kreuzberg requires ONNX Runtime version 1.24+ for embeddings. All other Kreuzberg features work without ONNX Runtime.

Supported Formats

90+ file formats across 8 major categories with intelligent format detection and comprehensive metadata extraction.

Office Documents

Category Formats Capabilities
Word Processing .docx, .docm, .dotx, .dotm, .dot, .odt, .pages Full text, tables, lists, images, metadata, styles
Spreadsheets .xlsx, .xlsm, .xlsb, .xls, .xla, .xlam, .xltm, .xltx, .xlt, .ods, .numbers Sheet data, formulas, cell metadata, charts
Presentations .pptx, .pptm, .ppsx, .potx, .potm, .pot, .key Slides, speaker notes, images, metadata
PDF .pdf Text, tables, images, metadata, OCR support
eBooks .epub, .fb2 Chapters, metadata, embedded resources
Database .dbf Table data extraction, field type support
Hangul .hwp, .hwpx Korean document format, text extraction

Images (OCR-Enabled)

Category Formats Features
Raster .png, .jpg, .jpeg, .gif, .webp, .bmp, .tiff, .tif OCR, table detection, EXIF metadata, dimensions, color space
Advanced .jp2, .jpx, .jpm, .mj2, .jbig2, .jb2, .pnm, .pbm, .pgm, .ppm Pure Rust decoders (JPEG 2000, JBIG2), OCR, table detection
Vector .svg DOM parsing, embedded text, graphics metadata

Web & Data

Category Formats Features
Markup .html, .htm, .xhtml, .xml, .svg DOM parsing, metadata (Open Graph, Twitter Card), link extraction
Structured Data .json, .yaml, .yml, .toml, .csv, .tsv Schema detection, nested structures, validation
Text & Markdown .txt, .md, .markdown, .djot, .mdx, .rst, .org, .rtf CommonMark, GFM, Djot, MDX, reStructuredText, Org Mode, Rich Text

Email & Archives

Category Formats Features
Email .eml, .msg Headers, body (HTML/plain), attachments, UTF-16 support
Archives .zip, .tar, .tgz, .gz, .7z Recursive extraction, nested archives, metadata

Academic & Scientific

Category Formats Features
Citations .bib, .ris, .nbib, .enw, .csl BibTeX/BibLaTeX, RIS, PubMed/MEDLINE, EndNote XML, CSL JSON
Scientific .tex, .latex, .typ, .typst, .jats, .ipynb LaTeX, Typst, JATS journal articles, Jupyter notebooks
Publishing .fb2, .docbook, .dbk, .opml FictionBook, DocBook XML, OPML outlines
Documentation .pod, .mdoc, .troff Perl POD, man pages, troff

Complete Format Reference →

Code Intelligence (300+ Languages)

Feature Description
Structure Extraction Functions, classes, methods, structs, interfaces, enums
Import/Export Analysis Module dependencies, re-exports, wildcard imports
Symbol Extraction Variables, constants, type aliases, properties
Docstring Parsing Google, NumPy, Sphinx, JSDoc, RustDoc, and 10+ formats
Diagnostics Parse errors with line/column positions
Syntax-Aware Chunking Split code by semantic boundaries, not arbitrary byte offsets

Powered by tree-sitter-language-pack with dynamic grammar download. See TSLP documentation for the full language list.

Key Features

OCR with Table Extraction

Multiple OCR backends (Tesseract, EasyOCR, PaddleOCR) with intelligent table detection and reconstruction. Extract structured data from scanned documents and images with configurable accuracy thresholds.

OCR Backend Documentation →

Batch Processing

Process multiple documents concurrently with configurable parallelism. Optimize throughput for large-scale document processing workloads with automatic resource management.

Batch Processing Guide →

Password-Protected PDFs

Handle encrypted PDFs with single or multiple password attempts. Supports both RC4 and AES encryption with automatic fallback strategies.

PDF Configuration →

Language Detection

Automatic language detection in extracted text using fast-langdetect. Configure confidence thresholds and access per-language statistics.

Language Detection Guide →

Metadata Extraction

Extract comprehensive metadata from all supported formats: authors, titles, creation dates, page counts, EXIF data, and format-specific properties.

Metadata Guide →

AI Coding Assistants

Kreuzberg ships with an Agent Skill that teaches AI coding assistants how to use the library correctly. It works with Claude Code, Codex, Gemini CLI, Cursor, VS Code, Amp, Goose, Roo Code, and any tool supporting the Agent Skills standard.

Install the skill into any project using the Vercel Skills CLI:

npx skills add kreuzberg-dev/kreuzberg

The skill is located at skills/kreuzberg/SKILL.md and is automatically discovered by supported AI coding tools once installed.

Documentation

Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

Part of Kreuzberg.dev

  • Kreuzberg Cloud — managed extraction API with SDKs, dashboards, and observability.
  • kreuzcrawl — web crawling and scraping with HTML→Markdown and headless-Chrome fallback.
  • html-to-markdown — fast, lossless HTML→Markdown engine.
  • liter-llm — universal LLM API client with native bindings for 14 languages and 143 providers.
  • tree-sitter-language-pack — tree-sitter grammars and code-intelligence primitives.
  • alef — the polyglot binding generator that produces all per-language bindings.
  • Discord — community, roadmap, announcements.

License

Elastic License 2.0 (ELv2) - see LICENSE for details. See https://www.elastic.co/licensing/elastic-license for the full license text.

FAQ

What is Kreuzberg?

Kreuzberg is a polyglot document intelligence framework with a Rust core. It extracts text, metadata, and code intelligence from 90+ file formats and 300+ programming languages at native speeds without needing a GPU. It provides native bindings for Rust, Python, TypeScript/Node.js, Ruby, Go, Java, Kotlin, C#, PHP, Elixir, R, Dart, Swift, Zig, and C.

How does Kreuzberg differ from other document extraction tools?

  • Kreuzberg: Rust core, 90+ formats, 300+ languages, polyglot bindings, code intelligence via tree-sitter, VLM OCR, native speeds, no GPU needed
  • Apache Tika: Java-based, broader format support, but slower, no code intelligence, no VLM OCR
  • pdfplumber: Python-only, PDF focus, slower, no code intelligence
  • unstructured: Python-based, good format coverage, but slower, requires more dependencies

Kreuzberg's Rust core with SIMD optimizations and parallelism delivers 10-100x faster extraction than Python alternatives.

What are Kreuzberg's key features?

  • Code intelligence — Extract functions, classes, imports, symbols, docstrings from 300+ languages via tree-sitter
  • Extensible architecture — Plugin system for custom OCR backends, validators, post-processors, document extractors, renderers
  • Polyglot bindings — Native bindings for 14+ languages (Rust, Python, Node.js, Ruby, Go, Java, Kotlin, C#, PHP, Elixir, R, Dart, Swift, Zig, C)
  • 90+ file formats — PDF, Office documents, images, HTML, XML, emails, archives, academic formats across 8 categories
  • LLM intelligence — VLM OCR (GPT-4o, Claude, Gemini, Ollama), structured JSON extraction, embeddings via 143 LLM providers
  • OCR support — Tesseract (all bindings including WASM for browsers), PaddleOCR, EasyOCR, VLM OCR, extensible via plugin API
  • High performance — Rust core with pure-Rust PDF, SIMD optimizations, full parallelism
  • Flexible deployment — Library, CLI tool, REST API server, or MCP server
  • TOON wire format — Token-efficient serialization for LLM/RAG pipelines, ~30-50% fewer tokens than JSON
  • GFM-quality output — Comrak-based Markdown rendering with proper fenced code blocks, table nodes
  • Memory efficient — Streaming parsers for multi-GB files

What file formats does Kreuzberg support?

8 categories covering 90+ formats:

  • Documents — PDF, DOCX, DOC, ODT, RTF, Hangul
  • Office — XLSX, XLS, PPTX, PPT, ODS, iWork
  • Images — PNG, JPEG, TIFF, BMP, GIF, WebP
  • Web — HTML, XML, XHTML, SVG
  • Emails — MSG, EML, PST
  • Archives — ZIP, TAR, GZ, TGZ, 7Z
  • Academic — LaTeX, BibTeX, RIS
  • Code — 300+ programming languages via tree-sitter

How do I get started?

Choose your platform:

Python:

pip install kreuzberg

See Python docs

Node.js:

npm install @kreuzberg/node

See Node.js docs

Rust:

cargo add kreuzberg

See Rust docs

Docker:

docker pull ghcr.io/kreuzberg-dev/kreuzberg:latest

See Docker docs

What LLM/VLM providers are supported?

143 providers including:

  • OpenAI — GPT-4o (vision), text models
  • Anthropic — Claude (vision), Claude 3.5 Sonnet
  • Google — Gemini (vision), Gemini 2.0 Flash
  • Local engines — Ollama, LM Studio, vLLM, llama.cpp
  • Cloud providers — Fireworks, Together, Groq, OpenRouter
  • All OpenAI-compatible endpoints

What OCR backends are available?

  • Tesseract — All bindings, including Tesseract-WASM for browsers
  • PaddleOCR — All native bindings (Python, Node.js, etc.)
  • EasyOCR — Python binding
  • VLM OCR — 143 vision model providers (GPT-4o, Claude, Gemini, Ollama local)
  • Custom OCR — Extensible via plugin API

What is the TOON wire format?

TOON is Kreuzberg's token-efficient serialization format for LLM/RAG pipelines. It uses ~30-50% fewer tokens than JSON, making it ideal for:

  • Large document processing
  • RAG system integration
  • LLM context window optimization
  • Cost reduction in API calls

What is code intelligence extraction?

Kreuzberg extracts semantic code information via tree-sitter:

  • Functions — Names, parameters, return types, docstrings
  • Classes — Names, methods, inheritance, properties
  • Imports — Module names, import paths
  • Symbols — Variables, constants, type definitions
  • Docstrings — Documentation comments

Results in ExtractionResult.code_intelligence with semantic chunking.

Does Kreuzberg work in browsers?

Yes! The WASM package (@kreuzberg/wasm) supports browsers, Deno, and Cloudflare Workers with:

  • PDF, Excel, archives, all office formats
  • Real Tesseract OCR via WASI build
  • Only ORT-dependent features excluded (PaddleOCR, layout detection, embeddings, auto-rotate)

What deployment options are available?

  • Library — Use as a dependency in your application
  • CLI — Cross-platform binary for batch processing
  • REST API server — HTTP endpoint for document extraction
  • MCP server — Model Context Protocol server for AI assistants
  • Docker — Official images with API, CLI, and MCP modes

What languages have native bindings?

Language Package Manager Status
Rust Cargo ✅ Core library
Python PyPI ✅ Full support
Node.js npm (NAPI-RS) ✅ Fastest performance
WASM npm ✅ Browser/Deno/CF Workers
Ruby RubyGems ✅ Native bindings
Go Go modules ✅ FFI bindings
Java Maven Central ✅ Foreign Function API
Kotlin Maven Central ✅ Coroutine-based
C# NuGet ✅ .NET 6.0+
PHP Composer ✅ PHP 8.2+
Elixir Hex ✅ OTP integration
R r-universe ✅ extendr bindings
Dart/Flutter pub.dev ✅ flutter_rust_bridge
Swift SPM ✅ macOS 13+/iOS 16+
Zig build.zig.zon ✅ Idiomatic API
C (FFI) pkg-config/CMake ✅ Header + shared lib

What platforms are supported?

All bindings support:

  • Linux — x86_64 and aarch64
  • macOS — ARM64
  • Windows — x64 (most bindings)

Precompiled binaries included for all architectures.

What license does Kreuzberg use?

Elastic-2.0 License — open-source with commercial use restrictions. See LICENSE for details.

Where can I get help?