How to compare two texts online?

Paste your texts in left and right panels. Our diff tool instantly highlights additions, deletions, and modifications line-by-line with color coding.

What is a diff tool used for?

Diff tools compare files, code, or text to find differences. Used for code review, document comparison, debugging, and tracking changes between versions.

Can I compare code with syntax highlighting?

Yes, our diff tool supports syntax highlighting for 50+ programming languages including JavaScript, Python, Java, C++, and more.

Is the diff tool safe to use?

Yes, completely safe. All text comparison happens locally in your browser. No files or content are uploaded to our servers, ensuring complete privacy.

Text Diff Tool

Compare text files side by side with highlighted differences. Perfect for code reviews, document comparison, and text analysis.

Ignore whitespaceIgnore case

📄 Original Text

Lines: 1 | Characters: 0

📄 Modified Text

Lines: 1 | Characters: 0

Enter text to compare

Paste your original and modified text above

Legend

+ Added lines

- Removed lines

~ Modified lines

Unchanged lines

Complete Text Comparison and Diff Guide

📖 Understanding Text Differences

Text comparison (diff) tools identify and visualize differences between two versions of text. Essential for code reviews, document editing, version control, and content management.

Why Use Diff Tools?

• Code Reviews: Identify changes in software development
• Document Editing: Track revisions in text documents
• Configuration Management: Compare config files
• Data Analysis: Compare datasets and reports
• Legal Documents: Track contract changes

Types of Changes

• Additions: New lines or content added
• Deletions: Lines or content removed
• Modifications: Existing content changed
• Moves: Content relocated within document

🎯 How to Use This Tool

Prepare Your Text

Paste your original text in the left panel and the modified version in the right panel. The tool works with any text content.

Configure Options

Choose comparison options: ignore whitespace differences, ignore case sensitivity, and select side-by-side or unified view mode.

Analyze Results

Review highlighted differences, check statistics, and understand the scope of changes. Use color coding to quickly identify change types.

Export or Share

Copy results for documentation, share findings with team members, or use insights for decision making and review processes.

Diff Algorithms and Comparison Methods

🔄 Myers Algorithm

Most common diff algorithm used by Git and many tools. Finds the shortest edit sequence (SES) to transform one text into another.

Pros: Optimal results, widely supported
Cons: Can be slow on large files

⚡ Hunt-McIlroy

Fast algorithm that finds longest common subsequence (LCS). Good for large files but may not produce minimal diffs.

Pros: Fast performance, handles large files
Cons: Less optimal diff output

🎯 Patience Diff

Used by Git with --patience flag. Produces more intuitive diffs for code by matching unique lines first.

Pros: Intuitive results, good for code
Cons: May be slower, specialized use

📝 Line-by-Line

Simple comparison that matches entire lines. Fast and easy to understand, used by our tool for real-time comparison.

Pros: Fast, simple, real-time
Cons: Less granular than word/character diff

🔤 Word-Level Diff

Compares individual words rather than lines. Provides more granular highlighting of changes within lines.

Pros: Granular detail, precise changes
Cons: More complex, can be overwhelming

🧬 Semantic Diff

Language-aware comparison that understands code structure. Used by advanced IDE tools for intelligent merging.

Pros: Context-aware, intelligent
Cons: Language-specific, complex setup

Version Control and Git Integration

📊 Git Diff Commands

Basic Diff Commands

git diff - Working vs staged

git diff --staged - Staged vs last commit

git diff HEAD - Working vs last commit

git diff branch1 branch2 - Compare branches

Advanced Options

git diff --word-diff - Word-level highlighting

git diff --patience - Use patience algorithm

git diff --ignore-whitespace - Ignore whitespace

git diff --stat - Show file statistics

File-Specific Diff

git diff filename - Specific file

git diff commit1 commit2 file - File between commits

git show commit:file - File at specific commit

🔧 Professional Workflows

Code Review Process

Standard workflow for reviewing changes:

Create feature branch from main
Make changes and commit regularly
Use diff tools to review changes
Create pull/merge request
Team reviews using diff views
Address feedback and iterate
Merge after approval

Merge Conflict Resolution

When Git can't automatically merge changes, diff tools help identify conflicting sections. Use three-way merge tools to see original, yours, and theirs side by side.

Release Management

Compare release branches to understand changes going to production. Generate changelogs from diff outputs and communicate updates to stakeholders.

Diff Best Practices and Performance Tips

✅ Best Practices

📏 Meaningful Comparisons

Compare related versions - avoid comparing completely different files. Use consistent formatting and line endings to reduce noise in diffs.

🎯 Focus on Important Changes

Use ignore options appropriately - ignore whitespace for code reviews, but keep it for documentation. Filter out generated files and build artifacts.

📝 Document Changes

Use diff outputs for documentation, changelog generation, and communicating changes to team members. Screenshot or export important comparisons.

🔍 Review Systematically

Review diffs line by line for critical changes. Use side-by-side view for understanding context, unified view for getting overview of all changes.

⚠️ Common Pitfalls

🌪️ Overwhelming Diffs

Large files or many changes can create overwhelming diff outputs. Break large changes into smaller, focused commits for easier review.

🎨 Formatting Noise

Automatic formatters can create noisy diffs that obscure real changes. Apply formatting separately from functional changes, use ignore options wisely.

🚫 Ignoring Context

Don't just look at changed lines - understand surrounding context. A small change might have big implications depending on where it occurs.

💾 Performance Issues

Very large files can cause performance problems. For huge files, consider using specialized tools or splitting into smaller sections.

Professional Use Cases and Applications

💻 Software Development

• Code review and pull request analysis
• Debugging by comparing working vs broken code
• Configuration file management
• API documentation updates
• Database schema migrations
• Refactoring impact assessment

📄 Content Management

• Document revision tracking
• Website content updates
• Marketing copy iterations
• Legal document changes
• Technical writing edits
• Translation comparisons

🔧 System Administration

• Configuration file comparisons
• Log file analysis
• Security policy updates
• Environment synchronization
• Backup verification
• System health monitoring

📊 Data Analysis

• Dataset version comparisons
• Report generation tracking
• CSV file change analysis
• Research data integrity
• Experiment result comparison
• Quality assurance testing

⚖️ Legal and Compliance

• Contract revision tracking
• Policy update documentation
• Regulatory compliance checks
• Audit trail maintenance
• Terms of service changes
• Privacy policy updates

🎓 Education and Research

• Student work comparison (plagiarism detection)
• Research paper revisions
• Curriculum development
• Lab report analysis
• Collaborative writing projects
• Peer review processes

Frequently Asked Questions

Q: What's the difference between side-by-side and unified view?

A: Side-by-side shows both versions in parallel columns, making it easy to see context and understand changes. Unified view shows all changes in a single column with +/- indicators, giving a compact overview of modifications.

Q: When should I ignore whitespace differences?

A: Ignore whitespace when comparing code where formatting changes aren't important, or when different editors/tools have modified indentation. Keep whitespace sensitive for documentation, configuration files, or when precise formatting matters.

Q: How accurate is this diff algorithm?

A: Our line-based algorithm is optimized for speed and real-time comparison. It's very good for most use cases but may not find the absolute minimal diff for complex changes. For production code reviews, consider using Git's built-in diff tools.

Q: Can I compare files larger than what fits in the text areas?

A: This web-based tool is designed for moderate-sized text comparisons. For very large files, consider using command-line tools like `diff`, `git diff`, or specialized software like Beyond Compare or WinMerge.

Q: Is my text data stored or sent to any servers?

A: No, all processing happens locally in your browser. Your text data never leaves your device, ensuring complete privacy and security. The comparison is performed using client-side JavaScript only.

Q: How do I handle complex merge conflicts in Git?

A: For complex conflicts, use three-way merge tools like `git mergetool` with tools like vimdiff, kdiff3, or VS Code. These show original, yours, theirs, and result views. Our tool can help understand changes before committing.

Q: What file formats work best with diff tools?

A: Plain text formats work best: source code, configuration files, CSV, JSON, XML, Markdown. Binary files (images, executables) need specialized tools. For structured data, consider formatting consistently before comparison.

Q: How can I automate diff generation in my workflow?

A: Use Git hooks, CI/CD pipelines, or scripts to automatically generate diffs for code reviews, deployment verification, or documentation. Tools like GitHub Actions can comment diff summaries on pull requests automatically.

Diff Tool