Getting started

JavaScript implementation of XSLTProcessor for browser environments and Node.js CLI. This package provides a complete implementation of the W3C XSLTProcessor API that can be used as a drop-in replacement for the native browser implementation.

Background

Chrome and other browsers are deprecating native XSLTProcessor support:

• Chrome 143+: XSLTProcessor starts showing deprecation warnings
• Chrome 164 (August 2027): Full removal of native XSLT support

This library ensures your XSLT-based applications continue to work regardless of browser support.

Features

• 1:1 Native API Compatibility: Drop-in replacement for native XSLTProcessor
• XSLT 1.0: Every element and function of the W3C XSLT 1.0 Recommendation, with the few gaps listed under Known Deviations
• XPath 1.0 Engine: Built-in XPath evaluator with all core functions
• xsl:output Serialization: transformToString() honors method, indent, doctype, CDATA sections and disable-output-escaping
• Zero Dependencies: The library has no runtime dependencies; only the xslt command line tool needs jsdom (an optional peer dependency)
• Multiple Formats: ESM, CommonJS, and browser IIFE bundles
• TypeScript Support: Includes TypeScript declarations

Documentation

The documentation is also published as a website with an interactive playground: https://xslt-processor.tradik.com/ (playground).

All guides are listed in the documentation index.

Installation

npm install @tradik/xslt-processor

The library itself has no dependencies. The xslt command line tool also needs jsdom (an optional peer dependency, >=25), see CLI Usage.

Quick Start

Browser via CDN (Recommended)

Use a CDN for the easiest browser integration - no build step required:

<!-- jsDelivr (recommended) -->
<script src="https://cdn.jsdelivr.net/npm/@tradik/xslt-processor@1/dist/xslt-processor.browser.min.js"></script>

<!-- or unpkg -->
<script src="https://unpkg.com/@tradik/xslt-processor@1/dist/xslt-processor.browser.min.js"></script>

<script>
  // XSLTProcessor is the native one, or this polyfill when native XSLT is unavailable
  const processor = new XSLTProcessor();

  // Load and transform XML
  const parser = new DOMParser();
  const xslt = parser.parseFromString(xsltString, 'application/xml');
  const xml = parser.parseFromString(xmlString, 'application/xml');

  processor.importStylesheet(xslt);
  const result = processor.transformToFragment(xml, document);
  document.getElementById('output').appendChild(result);
</script>

The bundle defines the global XsltProcessorLib (all module exports) and calls installGlobal(): window.XSLTProcessor is replaced only when the browser has no working native implementation. To always use this implementation, call XsltProcessorLib.installGlobal(true) or use new XsltProcessorLib.XSLTProcessor().

CDN URLs:

Tip: Use @1 for the latest 1.x version, or an exact version such as @1.1.3 for pinning.

Browser (Local Install)

If you prefer local installation:

<script src="node_modules/@tradik/xslt-processor/dist/xslt-processor.browser.min.js"></script>
<script>
  // XSLTProcessor is now available globally
  const processor = new XSLTProcessor();
  // ...
</script>

ESM Module

import { XSLTProcessor, installGlobal } from '@tradik/xslt-processor';

// Optional: Force install as global XSLTProcessor
installGlobal();

// Or use directly
const processor = new XSLTProcessor();
const parser = new DOMParser();

// Load and parse XSLT stylesheet
const xsltText = await fetch('template.xsl').then(r => r.text());
const xsltDoc = parser.parseFromString(xsltText, 'application/xml');
processor.importStylesheet(xsltDoc);

// Load and parse XML source
const xmlText = await fetch('data.xml').then(r => r.text());
const xmlDoc = parser.parseFromString(xmlText, 'application/xml');

// Transform
const fragment = processor.transformToFragment(xmlDoc, document);
document.getElementById('output').appendChild(fragment);

CommonJS

const { XSLTProcessor } = require('@tradik/xslt-processor');

const processor = new XSLTProcessor();
// ...

Node.js

Node.js has no DOM, so bring one such as jsdom. The filesystem loader example is a complete Node.js script, and the API Reference covers every method.

CLI Usage

The package includes a command-line tool for transforming XML documents.

Without Node.js, use the standalone executable attached to every GitHub release (Linux x64/arm64, macOS x64/arm64, Windows x64), installed with a checksum check:

curl -fsSL https://raw.githubusercontent.com/spagu/XSLT-Processor/main/scripts/install.sh | bash

See Standalone executables for manual installation. With Node.js, the command line tool needs a DOM implementation, so install jsdom next to the package. It is an optional peer dependency: library users do not need it. Without it, xslt exits with an explanation instead of a stack trace.

# Global installation
npm install -g @tradik/xslt-processor jsdom

# Transform XML with XSLT
xslt data.xml template.xsl

# Save output to file
xslt data.xml template.xsl -o result.html

# With parameters
xslt data.xml template.xsl -p title="My Page" -p count=10

# Format output with indentation
xslt data.xml template.xsl -f -o output.html

# Override the output method and drop the XML declaration
xslt data.xml template.xsl --method text
xslt data.xml template.xsl --no-declaration

See Command Line Tool for all options, the base directory, xsl:include/document() resolution and input encodings.

Known Deviations

The main differences from XSLT 1.0 / XPath 1.0 and from libxslt:

• xsl:number ignores lang and letter-value;
• unparsed-entity-uri() always returns '';
• numbers convert to strings in the XPath 1.0 form (10000000000), where libxslt writes 1e+10.

Details and workarounds: Known Deviations.

Contributing and Security

• CONTRIBUTORS.md - how to contribute
• CODE_OF_CONDUCT.md
• SECURITY.md - reporting vulnerabilities and the threat model
• CHANGELOG.md - release history

License

BSD-3-Clause License - see LICENSE.md for details.

Related

• MDN XSLTProcessor
• libxslt - Reference implementation in C