Code Compare Tool

This tool understands your code structure, not just text differences:

🎯 What you get:

• See function changes: Automatically detects new, deleted, or modified functions and methods
• Focus on what matters: Filters out formatting changes to show only meaningful code modifications
• Visual organization: Shows changes organized by functions, classes, and code elements
• Smart conflict resolution: Merge changes safely with validation warnings

💡 Why this helps your workflow:

• Faster code reviews: Instantly see what functionality changed vs just formatting
• Safer refactoring: Verify that code restructuring didn't break anything important
• Better merge conflicts: Understand exactly what conflicts need resolution
• Cleaner pull requests: Focus reviewers on the changes that actually matter

🔧 Works with your favorite languages:

• Advanced analysis: JavaScript, TypeScript, Python, Java, C# with full function detection
• Universal support: Any programming language with intelligent line-by-line comparison
• No setup required: Just paste your code or drag & drop files

Perfect for: Daily code reviews, understanding large changes, preparing merge requests, and validating refactoring work.

For technical details about the parsing engines and AST analysis, see the advanced FAQ below.

Smart function detection for popular languages, universal support for everything else:

🎯 Advanced Analysis (Function & Class Detection):

• JavaScript & TypeScript: Detects functions, classes, variables, arrow functions, React components
• Python: Finds functions, classes, methods, imports, decorators
• Java: Identifies classes, methods, fields, constructors, packages
• C#: Recognizes classes, methods, properties, enums, using statements

⚡ Works with Any Language:

• All Programming Languages: C++, Go, Rust, PHP, Ruby, Swift, Kotlin, Scala, and any other language
• Configuration Files: JSON, YAML, XML, HTML, CSS, SQL
• Text Formats: Markdown, documentation, config files

📊 What this means for you:

• Best experience: JavaScript, TypeScript, Python, Java, C# show detailed function changes
• Still great: All other languages get intelligent line-by-line comparison
• No limitations: Upload any code file and get useful diff analysis

🚀 How to use:

1. Paste code directly into the editor panels
2. Drag & drop files for automatic language detection
3. Select language manually for optimal analysis
4. View results in both visual diff and structured tree

Perfect for: Web developers (React, Vue, Angular), backend developers (Node.js, Python, Java), mobile developers (Swift, Kotlin), and anyone working with code files.

Simple click-to-merge system with smart validation to keep your code working:

⚡ Easy Conflict Resolution:

• Click merge buttons: Accept changes from either side with a single click
• See what you're merging: Clear visual highlighting shows exactly what will change
• Safe merging: Automatic warnings if a merge might break your code structure
• Multiple merges: Make several merge decisions and see the combined result

🛡️ Smart Safety Features:

• Prevents broken code: Warns you before merging changes that could break JSON, YAML, or code syntax
• Undo anytime: Reset button restores everything back to original state instantly
• Visual feedback: Clear indication of what's been merged vs. original content
• Validation checking: Different safety rules for different file types

🚀 Workflow Integration:

• Export merged results: Download the final merged file ready for your project
• Share with team: Send diff URLs to teammates for review and collaboration
• Git workflow ready: Merged files work perfectly with git commit and push
• Before/after comparison: Always see original, modified, and merged versions

💡 Best practices:

1. Review changes first: Understand what each side changed before merging
2. Use the tree view: See function-level changes in the analysis panel
3. Test merge safety: Pay attention to validation warnings
4. Export when ready: Download merged file when you're satisfied with results

Perfect for: Resolving git merge conflicts, combining code changes from multiple developers, and preparing clean merges before committing to version control.

100% secure and private - your code never leaves your browser:

🔒 Complete Privacy:

• No uploads: All analysis happens locally in your browser, never sent to servers
• No tracking: We don't collect, store, or analyze your code in any way
• No accounts: No sign-up required, no user data collection
• Memory cleanup: Code is automatically cleared when you close the tab

🛡️ Security Features:

• Local processing: Everything runs on your computer, not on external servers
• Browser sandbox: Code analysis runs in secure browser environment
• No external calls: Tool works completely offline after initial page load
• Open source: Code is transparent and auditable

📤 Optional Sharing (Your Choice):

• URL sharing: Choose to share diffs via encoded URLs (data stays in URL fragment)
• No server storage: Shared URLs contain compressed data, not server references
• You control sharing: Only share what you want, when you want
• Temporary: Clear browser data to invalidate any shared URLs

Perfect for: Sensitive corporate code, proprietary projects, personal repositories, and any situation where code privacy is important.

Real-world scenarios where smart code comparison saves time and prevents errors:

👥 Code Review Workflows:

• Pull request reviews: Quickly see what functions and classes actually changed vs just formatting
• Team collaboration: Share diff URLs with teammates to discuss specific changes
• API change detection: Spot breaking changes before they reach production
• Focus reviews: Filter out noise to review only meaningful code modifications

🔧 Development & Refactoring:

• Safe refactoring: Verify that code restructuring preserved all functions and methods
• Merge preparation: Understand conflicts before attempting git merges
• Version comparison: Compare different versions to understand what changed over time
• Framework upgrades: Track changes when updating React, Vue, Angular, or other frameworks

🚀 Daily Development Tasks:

• Debug regression: Find exactly what changed between working and broken versions
• Understand changes: Quickly grasp what a large commit or PR actually does
• Clean commits: Prepare clean, reviewable commits by understanding your changes
• Documentation: Generate change summaries for release notes or documentation

🏢 Professional Workflows:

• Legacy modernization: Track progress when updating old codebases
• Compliance tracking: Document code changes for regulatory requirements
• Release management: Validate changes before production deployments
• Knowledge transfer: Help new team members understand codebase evolution

Perfect for: Daily code reviews, refactoring projects, merge conflict resolution, and any time you need to understand what really changed in your code beyond just text differences.

Export capabilities designed for development workflows:

📁 Download formats:

• Original code: Download left-side content with language-appropriate file extension
• Modified code: Download right-side content as a separate file
• Merged code: Export final merged result after line-level conflict resolution
• Automatic extensions: Smart file naming (.js, .ts, .py, .java, .cs, .txt based on language)

🔧 File handling:

• Language detection: Automatic file extension based on selected language
• UTF-8 encoding: Consistent character encoding for all exports
• Preserved formatting: Maintains original indentation and line endings
• Browser download: Standard browser download mechanism for all files

⚙️ Sharing options:

• URL sharing: Compressed, encoded URLs containing diff data
• Client-side sharing: Data encoded in URL fragment (no server storage)
• Language persistence: Share includes selected language for consistent analysis
• Copy & paste: Easy content copying with clipboard integration

🔗 Workflow integration:

• IDE compatibility: Files ready for import into any code editor
• Git workflows: Exported files work with standard git commands
• Code review: Export individual versions for review tools
• Documentation: Use exports for change documentation and team sharing

Technical Implementation:

• Browser File API for client-side downloads
• Base64 encoding for URL sharing
• Language-specific file extensions for proper IDE handling

Enterprise-grade security with complete client-side processing for maximum code protection:

🔒 Privacy guarantees:

• No server uploads: All code analysis happens locally in your browser
• No data tracking: We don't store, log, or analyze your code
• No network calls: Tool works completely offline after initial load
• Memory cleanup: Code is cleared when you close the browser tab

🛡️ Security features:

• Local processing: Uses Web Workers for secure background processing
• Sandboxed execution: Code analysis runs in isolated browser environment
• No external dependencies: All libraries bundled and verified
• CSP compliance: Content Security Policy prevents code execution

📤 Sharing options (optional):

• URL encoding: Share via compressed, encoded URLs (data stays in URL fragment)
• No server storage: Shared URLs contain encoded data, not server references
• User control: You choose what to share and with whom
• Temporary sharing: URLs can be invalidated by clearing browser data

🏢 Enterprise compliance:

• GDPR compliant: No personal data collection or processing
• SOC 2 ready: Suitable for enterprise security requirements
• Air-gapped compatible: Works in disconnected environments
• Source code available: Transparent, auditable codebase

Security Standards:

• OWASP Secure Coding Practices - Security development guidelines
• W3C Web Security - Web security standards
• RFC 6265 - HTTP State Management - Cookie security standards
• NIST Privacy Framework - Government privacy guidelines

Professional development scenarios where semantic code analysis provides maximum value:

👥 Code Review & Team Collaboration:

• Pull Request Analysis: Quickly identify functional changes vs formatting in GitHub/GitLab PRs
• Team Code Reviews: Focus reviewers on semantic changes that affect functionality
• API Change Detection: Spot breaking changes in public interfaces before deployment
• Merge Request Preparation: Understand changes before creating merge requests

🔧 Refactoring & Code Quality:

• Refactoring Validation: Ensure code restructuring preserved all functions, classes, and methods
• Legacy Code Modernization: Track progress when updating old codebases to modern standards
• Framework Migration: Analyze changes when upgrading React, Angular, Vue, or other frameworks
• Code Quality Improvement: Verify that optimization changes didn't break functionality

⚙️ Development Workflow Enhancement:

• Branch Comparison: Compare feature branches against main to understand scope of changes
• Version Analysis: Track changes between software versions for release notes
• Debugging Support: Identify exactly what changed between working and broken code versions
• Documentation Updates: Generate change summaries for technical documentation

🚀 DevOps & CI/CD Integration:

• Automated Code Analysis: Integrate semantic diff into CI pipelines for automated reviews
• Deployment Safety: Verify changes before production deployments
• Configuration Management: Track changes in infrastructure-as-code and config files
• Rollback Planning: Understand what needs to be reverted in case of issues

📊 Enterprise Development:

• Compliance Auditing: Track code changes for regulatory compliance requirements
• Security Review: Identify security-relevant changes in authentication, authorization, or data handling
• Performance Analysis: Spot changes that might affect application performance
• Architecture Evolution: Track architectural changes across large codebases

Perfect for development teams using: Git workflows, agile development, continuous integration, code review processes, and complex multi-developer projects where understanding change impact is critical.

Multi-engine parsing architecture for technical users who want implementation details:

🔬 Parser Technology Stack:

• JavaScript/TypeScript: Full AST analysis using TypeScript Compiler API with function, class, variable, and arrow function detection
• Python: Enhanced regex-based parser extracting functions, classes, variables, imports, and decorators with position tracking
• Java: Advanced regex patterns for classes, methods, fields, imports, and annotations with visibility modifiers
• C#: Comprehensive regex parser supporting classes, enums, methods, properties, and using statements
• Multi-language engine: Lezer parser integration for incremental parsing with Babel fallbacks

⚙️ Analysis Pipeline:

• Performance optimization: 50KB threshold automatically switches from AST parsing to optimized text diff
• Multi-threaded processing: Background analysis using intelligent fallbacks when advanced parsing fails
• Memory management: Efficient handling with intelligent caching and cleanup for large codebases
• Position tracking: Precise line/column location data for all detected code elements

🌳 Structured Analysis Output:

• Interactive diff tree: Hierarchical view categorizing changes by functions, classes, methods, fields, properties, and enums
• Change statistics: Real-time counts of added, deleted, and modified code elements with detailed descriptions
• Element categorization: Visual badges and color coding for different types of code structures
• Expandable metadata: Click to expand and see additional information about each detected change

🎯 Architecture Patterns:

• Intelligent fallbacks: Automatic failover from AST → regex → text analysis based on file size and complexity
• Language-specific validation: Different merge validation rules for different programming languages and file formats
• Client-side processing: All analysis happens in browser using optimized algorithms and Web Workers
• Extensible design: Parser architecture allows for adding new language support and analysis capabilities

Technical References:

• TypeScript Compiler API - AST manipulation and analysis
• Lezer Parser Generator - Incremental parsing for large codebases
• Myers Algorithm - Diff algorithm implementation
• Babel AST Explorer - Understanding JavaScript/TypeScript syntax trees