Skip to content

FreeXmlToolkit Documentation

Last Updated: March 2026 | Version: 1.6.3

Welcome

FreeXmlToolkit is a free desktop application for working with XML files. It helps you edit, validate, transform, and secure your XML documents - all in one place.

FreeXmlToolkit Main Window Screenshot: Main application window

What Can You Do With FreeXmlToolkit?

  • Edit XML files with smart auto-completion and syntax highlighting
  • Validate XML against XSD schemas to check for errors
  • Transform XML into other formats (HTML, PDF, Text)
  • Sign XML documents with digital certificates
  • Create business rules with Schematron validation
  • Generate documentation from your XSD schemas

Works On All Platforms

FreeXmlToolkit is available for Windows, macOS, and Linux in multiple formats. Choose the one that works best for you.

Windows

Format Architecture Description
.exe x64, ARM64 Installer - Standard setup wizard. No admin rights required. Recommended for most users.
.msi x64, ARM64 MSI Package - For enterprise deployment and silent installation via Group Policy.
.zip x64, ARM64 Portable - No installation needed. Extract and run. Good for USB drives or restricted systems.

macOS

Format Architecture Description
.dmg Intel (x64), Apple Silicon (ARM64) Disk Image - Standard macOS installation. Drag to Applications folder.
.pkg Intel (x64), Apple Silicon (ARM64) Package Installer - Guided installation wizard. Useful for managed deployments.
.zip Intel (x64), Apple Silicon (ARM64) Portable - No installation needed. Extract and run the app directly.

Linux

Format Architecture Description
.deb x64, ARM64 Debian Package - For Ubuntu, Debian, Linux Mint. Install with sudo dpkg -i or double-click.
.rpm x64, ARM64 RPM Package - For Fedora, Red Hat, openSUSE. Install with sudo rpm -i or dnf install.
.zip x64, ARM64 Portable - No installation needed. Extract and run. Works on any Linux distribution.

Note: Choose the architecture that matches your computer: - x64 - Most computers (Intel/AMD processors) - ARM64 - Newer ARM-based computers (Apple Silicon Macs, Windows on ARM, Raspberry Pi 4/5)


Feature Overview

XML Editor

Edit your XML files with professional tools:

Feature What It Does
Auto-Completion Suggests valid elements and attributes as you type
Syntax Highlighting Colors your XML for easier reading
Instant Validation Shows errors immediately as you edit
Find & Replace Search and replace text in your documents
Code Folding Collapse sections to focus on what matters

Learn more: XML Editor Guide | Editor Features

JSON Editor

Edit and validate JSON files with multiple format support:

Feature What It Does
Multi-Format Support Edit JSON, JSONC (with comments), and JSON5
Tree View Navigate JSON structure visually
JSONPath Queries Extract data using JSONPath expressions
Schema Validation Validate against JSON Schema
Hover Information See JSONPath and type info on hover

Learn more: JSON Editor Guide

XSD Schema Tools

Work with XML Schema files:

Feature What It Does
Visual Schema Viewer See your schema as an interactive diagram
Documentation Generator Create HTML documentation from schemas
Sample XML Generator Generate valid sample XML files
Schema Flattening Combine multiple schema files into one

Learn more: XSD Tools Guide | XSD Validation

XSLT Transformation

Convert XML into other formats:

Feature What It Does
Multi-Format Output Generate XML, HTML, Text, or JSON
Live Preview See results as you work
Modern XSLT Support Uses the latest XSLT 3.0 standard
Multi-File Batch Processing Process multiple XML files with one XQuery using collection()

Learn more: XSLT Viewer | XSLT Developer

PDF Generation

Create professional PDF documents:

Feature What It Does
XSL-FO Support Use XSL-FO stylesheets for formatting
High-Quality Output Professional PDF generation

Learn more: PDF Generation Guide

Digital Signatures

Sign and verify XML documents:

Feature What It Does
Create Certificates Generate your own signing certificates
Sign Documents Add digital signatures to XML files
Verify Signatures Check if signed documents are valid

Learn more: Digital Signatures Guide

Schematron Validation

Define custom business rules:

Feature What It Does
Business Rules Validate beyond basic XML structure
Visual Rule Builder Create rules without writing code
Detailed Reports Get clear validation results

Learn more: Schematron Guide


Getting Started

Installation

  1. Download the installer for your operating system from the releases page
  2. Run the installer (no administrator rights required on Windows)
  3. Launch FreeXmlToolkit from your applications menu

Your First Steps

  1. Open an XML file: Use File → Open or drag a file into the window
  2. Load a schema (optional): Click the folder icon in the XSD Schema section
  3. Start editing: Type < to see auto-completion suggestions
  4. Validate: Click "Validate" to check your document for errors

Sample Files

The application includes example files in the examples/ folder to help you get started:

  • xml/ - Sample XML documents
  • xsd/ - Sample XSD schemas
  • xslt/ - Sample transformation stylesheets
  • schematron/ - Sample business rules

Troubleshooting

Application Does Not Start (Windows)

On some Windows computers, the application may fail to start or crash immediately after launch. This is typically caused by incompatible graphics drivers.

What to try:

  1. Update your graphics drivers -- Visit your GPU manufacturer's website (NVIDIA, AMD, or Intel) and install the latest driver for your graphics card.
  2. Try the portable version -- If you used the installer (.exe or .msi), try the portable (.zip) version instead.
  3. Report the issue -- If the problem persists, please report it on the project's GitHub Issues page with your Windows version and graphics card model.

Note: Starting with version 1.6.3, FreeXmlToolkit automatically falls back to software rendering if your graphics hardware is not fully compatible. This resolves most startup crashes on Windows.

Application Looks Blurry or Slow

If the interface appears blurry or animations are slow, your system may be using software rendering instead of hardware acceleration. Updating your graphics drivers usually resolves this.


Keyboard Shortcuts

Shortcut Action
Ctrl+S Save file
Ctrl+Z Undo
Ctrl+Y Redo
Ctrl+F Find text
Ctrl+H Find and replace
< Open auto-completion
Enter Accept suggestion
Escape Close popup

Documentation Pages

Feature Guides

Page Description
XML Editor How to edit XML files
XML Editor Features Detailed editor features
JSON Editor How to edit JSON files
XSD Tools Working with XML schemas
XSD Validation Validating XML against schemas
XSLT Viewer Quick XSLT transformations
XSLT Developer Full XSLT/XQuery development environment
PDF Generator Creating PDF documents
Digital Signatures Signing XML documents
Schematron Support Business rule validation

Productivity Tools

Page Description
Auto-Completion (IntelliSense) Smart suggestions while typing
Favorites System Quick access to your files
Template Management Reusable code snippets
Schema Support Supported schema formats

Reference

Page Description
Security Features Built-in protections against XML attacks
Technology Stack Libraries and versions used
Third-Party Licenses License information

Need Help?

  • Browse the documentation pages listed above
  • Check the example files included with the application
  • Report issues on the project's GitHub page

Editors: XML Editor | XML Features | JSON Editor | XSD Tools | XSD Validation | XSLT Viewer | XSLT Developer | PDF/FOP | Signatures

Features: IntelliSense | Schematron | Schema Support | Favorites | Templates

Reference: Security | Tech Stack | Licenses