FreeXmlToolkit - Your Complete XML Workstation

FreeXmlToolkit is a free, open-source desktop workstation for XML: edit, validate, transform, debug and document XML, XSD, XSLT, XQuery, Schematron and JSON in one application - on Windows, macOS and Linux.

⬇ Download the latest release – Windows (.exe/.msi/portable), macOS (.dmg/.pkg, Apple Silicon & Intel), Linux (.deb/.rpm/portable) – or via scoop install freexmltoolkit / brew install --cask karlkauc/tap/freexmltoolkit (details). Full guide: karlkauc.github.io/FreeXmlToolkit.

Highlights

Visual XSD editor Design schemas as a graphical diagram or a tree, with type editor, facets, documentation and undo for every change. XSD 1.0 and 1.1.
Schema-aware XML editor IntelliSense that offers only what the schema allows at the caret, live validation while you type, and three views of one document: Text, Tree and an XMLSpy-style Grid that shows repeating elements as editable tables.
XSLT, XQuery and Schematron debugger Breakpoints (conditional, hit counts, logpoints), stepping, variables, watches, call stack, inline values and coverage - right in the editor.
Validation that explains itself XSD 1.1, Schematron with Quick Fixes (SQF), JSON Schema, batch validation of whole folders, and a Schema Library with OASIS XML catalogs that resolves imports without touching your files.
Transformations XSLT 3.0, XPath 3.1 and XQuery 3.1 with Saxon, live preview, XProc 3.0 pipelines, and a Query Console for ad-hoc XPath/XQuery (Ctrl+K).
PDF with Apache FOP XSL-FO to PDF with in-app preview, the intermediate FO and every FOP message at hand, and PDF/A-1b output.
Schema documentation, analysis and test data HTML, PDF or Word documentation from XSD, schema analysis with quality score and reports, and sample XML generated from any schema.
XML digital signatures Sign and verify documents, create certificates.

Features

XML and JSON Editing

• Text, Tree and Grid views of one document with a shared undo history
• Context-sensitive IntelliSense from the bound XSD: elements, attributes and enumeration values
• Properties Inspector showing the schema facts (type, cardinality, facets, documentation) of the node at the caret
• Code folding, syntax highlighting, formatting, search across all views
• JSON (and JSON5) with the same Text / Tree / Grid views and JSON Schema validation
• Templates for new files and Favorites for the files you use often

Schemas

• Graphical and tree editing of XSD with a type library, type editor and facet panel
• Schema Library: namespace-to-schema mappings, OASIS catalogs and a schema cache; imports and includes resolve transitively (local, HTTP or by namespace URL)
• HTML documentation, schema analysis (statistics, quality checks, identity constraints; export as CSV, JSON, HTML, PDF or Excel), sample XML generation and schema flattening

Validation

• XSD 1.0 / 1.1 validation with line-precise problems, live while you type
• Schematron (ISO, via SchXslt) with Schematron Quick Fixes applied as one undo step
• JSON Schema (Draft-07, 2019-09, 2020-12)
• Batch validation of whole folders

Transform, Query and Debug

• XSLT 3.0 / XPath 3.1 / XQuery 3.1 (Saxon HE) with live preview, parameters and HTML/text/XML output
• XProc 3.0 pipelines (XML Calabash)
• Query Console for XPath/XQuery against the open document
• Interactive debugger for XSLT, XQuery and Schematron: conditional breakpoints, logpoints, stepping, watches, call stack, "explain match", output-to-source mapping and coverage

Output and Security

• PDF generation with Apache FOP, in-app preview, PDF/A-1b
• XML digital signatures: sign, verify, create certificates

Not Supported

• DTD and RELAX NG - use XSD, Schematron or JSON Schema instead.

Getting Started

Download

1. Go to the Releases page (or use the download buttons on the documentation home page)
2. Download the package for your operating system:
   • Windows (x64): .exe installer (no administrator rights required), .msi for managed deployments, or the portable …windows-x64-app-image….zip
   • macOS (Apple Silicon arm64 or Intel x64): .dmg (drag to Applications), .pkg installer, or the portable app-image .zip — all signed with a Developer ID and notarized by Apple
   • Linux (x64): .deb (sudo dpkg -i …), .rpm (sudo rpm -i …), or the portable app-image .zip
3. Run the installer, or extract the portable ZIP to a folder and start FreeXmlToolkit from there

The packages bundle their own Java runtime - nothing else to install.

Install with a Package Manager

Windows – Scoop

scoop bucket add karlkauc https://github.com/karlkauc/scoop-bucket
scoop install freexmltoolkit

macOS – Homebrew

brew install --cask karlkauc/tap/freexmltoolkit

Package-manager installations are updated by the package manager (scoop update freexmltoolkit, brew upgrade --cask freexmltoolkit). The app still tells you when a new version is out and shows the matching command, but it does not replace its own files.

Coming soon: winget (Windows) and Flathub (Linux) – the submissions are in preparation.

Build from Source

Requires JDK 25 with JavaFX (e.g. Liberica Full JDK):

git clone https://github.com/karlkauc/FreeXmlToolkit.git
cd FreeXmlToolkit
./gradlew run

First Steps

The window is a single workspace: the activity bar on the left switches the side panel (Explorer, Search, Favorites, Validation, Transform, Schema, Schema Library, PDF/FOP, Signature, Settings), the center holds your file tabs with Text / Tree / Graphic views, the Properties inspector sits on the right, and the menu bar (File · Edit · View · Tools · Help) has every action.

• Open a file with Ctrl+O, the Explorer panel, or drag and drop
• Validate with F8 - problems appear in the Validation panel
• Run an XSLT, XQuery or XProc document with Ctrl+Enter, or pick a stylesheet in the Transform panel
• Debug a stylesheet, query or Schematron with Shift+F5
• On first start, Open an Example on the welcome page loads ready-made sample files; more are in the examples folder of the installation

All shortcuts: Keyboard Shortcuts.

Getting Help

• Documentation: the user guide, including What's New and FAQ & Troubleshooting
• In the app: the Help menu (F1)
• Bugs, ideas and questions: the Issues page

Privacy

FreeXmlToolkit sends anonymous usage statistics and error reports (never file names, paths or document content). Both are on by default and can be switched off under Settings → Privacy. See Privacy & Anonymous Telemetry for exactly what is sent.

Code Signing

Code signing for the Windows releases is provided by SignPath Foundation (being set up); the Code Signing Policy describes what is signed, by whom, and which network connections the application makes.

Support the Project

FreeXmlToolkit is free and open source, and it will stay that way. If it saves you time at work, please consider sponsoring its development on GitHub — sponsorships directly fund maintenance, bug fixes and new features.

Not able to sponsor? You can still help a lot:

• ⭐ Star the repository on GitHub
• 🐞 Report bugs and suggest features
• 📣 Tell colleagues who work with XML about it

Inside the app you find the sponsor link under Help → Sponsor this Project, in the About dialog and in Settings → Support the Project.

Contributing

Contributions are welcome - bug reports, feature ideas, documentation and code. For code, open an issue first for larger changes; ./gradlew test runs the test suite.

License

This project is licensed under the Apache License 2.0 - see the LICENSE.md file for details.

Acknowledgments

FreeXmlToolkit is built on many excellent open-source projects, among them JavaFX, Saxon (XSLT/XQuery), XML Calabash (XProc), Apache Xerces (XSD 1.1), ph-schematron, Apache FOP, Apache Santuario and RichTextFX. The full list with licenses is part of the documentation.