Code Diff Viewer
A professional text comparison editor based on Monaco Editor providing advanced code difference viewing and editing capabilities. Supports syntax highlighting, side-by-side comparison, inline editing, and more, ideal for code review, version comparison, document proofreading, and precise text difference analysis.
Key Features
Monaco Editor Core
Powered by Visual Studio Code's editor core Monaco Editor, providing the same editing experience as VS Code. Supports:
- Intelligent code completion
- Syntax highlighting
- Code folding
- Multi-cursor editing
- Find and replace
- Keyboard shortcuts
VS Code users can start working seamlessly.
Side-by-Side Comparison Mode
Displays original and modified versions in left-right panes with highlighted differences:
- Red background: Deleted content
- Green background: Added content
- Yellow border: Modified lines
- Connection lines: Show correspondence relationships
Difference annotations are precise to character level, making it easy to spot subtle changes.
Bidirectional Editing
Unlike read-only diff viewers, this tool supports direct editing of both sides:
- Left original version is editable (originalEditable: true)
- Right modified version is editable
- Real-time difference annotation updates
Suitable for correcting errors or merging changes during comparison.
Difference Navigation
Provides quick navigation features:
- Previous/Next difference buttons
- Difference statistics overview
- Scrollbar minimap showing difference distribution
Quickly locate change positions in large files.
Inline Difference View
Supports switching to inline mode (renderSideBySide: false), displaying differences in single-column format to save screen space. Suitable for narrow screen devices or when context focus is needed.
Syntax Highlighting
Automatically recognizes multiple programming languages and file types:
- JavaScript/TypeScript
- HTML/CSS/SCSS
- Python/Java/C++
- JSON/YAML/XML
- Markdown
- SQL
- 100+ languages
Detects automatically based on file extension or content, providing accurate syntax coloring.
Use Cases
Code Review
Review Pull Requests or Merge Requests by comparing old and new code versions. Intuitively view modifications, identify potential issues, and provide improvement suggestions.
Version Control
View file changes in Git, SVN, or other version control systems. Compare differences between commits to understand code evolution history.
Document Proofreading
Compare different document versions to check if editorial changes meet expectations. Suitable for reviewing technical documentation, API docs, user manuals, etc.
Configuration File Comparison
Compare configuration files between development, testing, and production environments to ensure configuration consistency and avoid environment issues.
Data Migration Validation
When migrating SQL scripts, JSON data, CSV files, etc., compare source and target files to verify data integrity and accuracy.
Usage Examples
Compare Code Before and After Refactoring
Scenario: Refactoring a function, need to confirm logic consistency.
Steps:
- Paste pre-refactoring code on the left
- Paste post-refactoring code on the right
- Observe green (added) and red (deleted) highlights
- Use navigation buttons to check each difference
- Confirm core logic unchanged, only code structure optimized
Resolve Merge Conflicts
Scenario: Git merge conflict, need manual resolution.
Steps:
- Paste base version code on the left
- Paste feature branch code on the right
- Compare differences to understand conflict causes
- Edit directly on the right, keeping needed changes
- Delete conflict markers, generate final version
API Documentation Change Tracking
Scenario: API interface upgrade, compare old and new documentation.
Steps:
- Paste old API documentation on the left (Markdown format)
- Paste new API documentation on the right
- View newly added interfaces (green annotations)
- View removed interfaces (red annotations)
- Record breaking changes, notify relevant developers
Keyboard Shortcuts
Common shortcuts (same as VS Code):
Editing Operations
Ctrl/Cmd + Z: UndoCtrl/Cmd + Shift + Z: RedoCtrl/Cmd + C/V/X: Copy/Paste/CutCtrl/Cmd + F: FindCtrl/Cmd + H: ReplaceAlt + Up/Down: Move line
Multi-Cursor
Alt + Click: Add cursorCtrl/Cmd + Alt + Up/Down: Add cursor above/belowCtrl/Cmd + D: Select next occurrence
Code Folding
Ctrl/Cmd + Shift + [: FoldCtrl/Cmd + Shift + ]: Unfold
Important Notes
Large File Performance
Comparing very large files (>1MB) may affect performance. Recommendations:
- Only compare necessary parts, delete irrelevant content
- Disable minimap to reduce rendering overhead
- Use modern browsers (Chrome, Edge) for better performance
Line Ending Differences
Windows (\r\n), Unix (\n), and Mac (\r) use different line endings, potentially causing entire files to appear red. Monaco Editor handles this automatically, but note whether actual differences are line ending inconsistencies.
Character Encoding
Ensure both files use the same character encoding (UTF-8 recommended) before comparison, otherwise garbled text or misjudged differences may occur.
Whitespace Characters
By default, displays differences in spaces and tabs. To ignore whitespace differences, manually adjust formatting after editing.
Comparison with Similar Tools
Compared to diffchecker.com, Beyond Compare, VS Code Diff Editor, and similar tools, this tool's features:
- Based on Monaco Editor, professional editing experience
- Supports bidirectional editing, not just viewing but also modifying
- 100+ language syntax highlighting, comprehensive coverage
- Pure browser operation, no software installation needed
- Local data processing, privacy secured
- Responsive layout, adapts to various screen sizes
Ideal for developers needing temporary code or text comparison with direct editing during the comparison process.
