BlazeDiff

BlazeDiff — a high-performance diff ecosystem for JavaScript applications. Originally built as a pixel-perfect image comparison library that's 1.5x faster than pixelmatch, BlazeDiff has evolved into a comprehensive suite of blazing-fast diff tools including image comparison, object diffing, web components, and React components for visualizing differences. Designed for visual testing, CI/CD pipelines, data validation, and any application requiring fast, accurate comparison operations.

Features

BlazeDiff provides a complete ecosystem of high-performance diff tools:

• Image Diff: Pixel-perfect image comparison with 1.5x performance improvement over pixelmatch
• Object Diff: Lightning-fast structural object comparison with detailed change tracking
• Web Components: Framework-agnostic components for displaying diffs in web applications
• React Components: Purpose-built React components for seamless diff visualization

Image Diff

BlazeDiff's image comparison is 1.5x faster than pixelmatch while maintaining identical accuracy and output quality. The performance improvement comes from:

• Block-based algorithm: Dynamic-sized blocks with processing only for changed areas
• Early exit optimization: Immediate return for identical images (Native C++ in Node)
• 32-bit integer comparisons: CPU vectorization for faster pixel matching
• Multiple format support: PNG, JPEG, and WebP when using Sharp transformer

Expected	Actual	Diff

100% API and Result Compatible: BlazeDiff is fully compatible with pixelmatch's API and produces identical results when using the YIQ color space flag.

Object Diff

BlazeDiff's object comparison provides blazing-fast structural diffing with comprehensive change detection:

• High-performance algorithm: Optimized for speed with intelligent key lookup strategies
• Detailed change tracking: Precise path tracking for nested object modifications
• Comprehensive type support: Handles primitives, objects, arrays, dates, regex, and circular references
• Memory efficient: Minimal overhead with consistent object shapes for V8 optimization

Original	Modified	Changes
{ "name": "John", "age": 30, "city": "NYC", "skills": ["JS", "TS"] }	{ "name": "John", "age": 31, "city": "SF", "skills": ["JS", "TS", "Go"], "active": true }	[ { "type": 2, "path": ["age"], "value": 31, "oldValue": 30 }, { "type": 2, "path": ["city"], "value": "SF", "oldValue": "NYC" }, { "type": 0, "path": ["skills", 2], "value": "Go", "oldValue": undefined }, { "type": 0, "path": ["active"], "value": true, "oldValue": undefined } ]

Difference Types:

• 0 (CREATE) - Property or array element was added
• 1 (REMOVE) - Property or array element was deleted
• 2 (CHANGE) - Property or array element value was modified

Use Cases

BlazeDiff is available in multiple packages to suit different use cases:

Core Libraries

• @blazediff/core - Core JavaScript library for pixel-perfect image comparison
• @blazediff/object - High-performance object diffing with detailed change tracking

Command Line Tools

• @blazediff/bin - CLI for image comparison with multiple format support

UI Components

• @blazediff/react - React components for displaying diffs in your applications
• @blazediff/ui - Framework-agnostic web components for diff visualization

Benchmarks

BlazeDiff delivers significant performance improvements across all components:

• Image Diff: ~50% faster than pixelmatch (up to 88% on identical images)
• Object Diff: ~30% faster than microdiff (up to 96% on identical arrays)
• CLI Tools: ~60% faster end-to-end performance with multi-format support

View Detailed Benchmarks - Complete performance data, test methodology, and hardware specifications.

Contributing

Contributions are welcome! Please see the Contributing Guide for details.

License

MIT License - see LICENSE file for details.

Acknowledgments

• Image diffing built on the excellent pixelmatch algorithm

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Built for high-performance difference detection across images and data structures