Diff Checker

Compare two texts and highlight the differences

How to Use This Tool

1

Paste Original Text

Enter or paste your original text in the left text area.

2

Paste Modified Text

Enter or paste your modified version in the right text area.

3

View Differences

The tool automatically highlights additions in green and deletions in red.

4

Choose View Mode

Switch between Unified view (inline changes) or Split view (side-by-side comparison).

5

Analyze Changes

See the count of additions and deletions to understand the scope of changes.

Pro Tips

  • Use the 'Swap' button to quickly switch the original and modified texts
  • Green highlights indicate added content, red highlights show removed content
  • Unified view shows changes inline, making it easier to follow the flow
  • Split view is better for comparing texts side-by-side
  • Load the sample to see an example of code refactoring differences
  • The tool performs line-by-line comparison for clear visualization

What is a Diff Checker?

A diff checker (difference checker) is a tool that compares two pieces of text, code, or documents to identify and highlight the differences between them. It's an essential utility for developers, writers, and anyone who needs to track changes between versions of text. Our diff checker uses advanced algorithms to perform line-by-line comparisons, showing additions, deletions, and modifications in an easy-to-understand visual format. Whether you're reviewing code changes, comparing document revisions, or verifying configuration updates, a diff checker helps you quickly understand what has changed and make informed decisions about those changes.

Key Features

Line-by-line comparison with visual highlighting

Unified view showing inline changes with context

Split view for side-by-side comparison

Color-coded differences (green for additions, red for deletions)

Line number tracking for easy reference

Character-level difference detection within changed lines

Statistics showing total additions and deletions

Swap function to reverse comparison direction

Support for any text format including code, JSON, XML

No file size limitations for comparison

Common Use Cases

Code Review: Compare code changes before merging pull requests, understand refactoring impacts, and ensure no unintended modifications were made during development cycles.

Document Versioning: Track changes between document revisions, compare drafts with final versions, and maintain an audit trail of content modifications for compliance or collaboration.

Configuration Management: Compare configuration files between environments (dev, staging, production), verify deployment changes, and troubleshoot configuration-related issues.

Content Editing: Review editorial changes in articles or documentation, track revisions made by team members, and ensure consistency across multiple versions of content.

Database Schema Changes: Compare SQL schema definitions, migration scripts, or database dumps to understand structural changes and plan database updates carefully.

API Contract Validation: Compare API responses or specifications to detect breaking changes, verify backward compatibility, and document API evolution over time.

Frequently Asked Questions

What's the difference between unified and split view?

Unified view displays changes inline within a single column, showing removed lines followed by added lines with surrounding context. This is similar to Git's default diff output and is ideal for following the flow of changes. Split view shows the original text on the left and modified text on the right, making it easier to compare texts side-by-side and see the overall structure of both versions simultaneously.

How accurate is the diff algorithm?

Our diff checker uses a line-by-line comparison algorithm that identifies exact matches, additions, and deletions. While it excels at detecting line-level changes, it may show a line as deleted and added if even a single character changes. For more granular comparisons, professional diff tools with word-level or character-level algorithms might be needed, but our tool handles most common comparison needs effectively.

Can I compare files instead of pasting text?

Currently, this tool works with pasted text for maximum compatibility and security. To compare files, simply open them in your text editor, copy the contents, and paste into the respective fields. This approach ensures your files remain private and never leave your device, as all processing happens locally in your browser.

Why do some unchanged lines appear as changed?

This can happen due to invisible differences like trailing whitespace, different line endings (Windows CRLF vs Unix LF), tab vs space indentation, or Unicode characters that look similar but have different codes. The diff checker detects these as changes because they are technically different, even if visually similar. Consider normalizing whitespace or line endings before comparison if this is an issue.

How can I share diff results with my team?

While the tool doesn't generate shareable links, you can: 1) Take screenshots of the diff view, 2) Copy both texts and share them for others to compare, 3) Use the unified view output which can be copied and pasted into documentation or chat, or 4) Save the comparison results as a document for sharing. For persistent diff sharing, consider using version control systems like Git.

What types of content work best with diff checking?

Diff checkers work best with text-based content including source code, configuration files, JSON/XML data, SQL queries, documentation, log files, and CSV data. They're less effective for binary files, heavily formatted documents (use specialized tools for Word docs), or content where visual layout matters more than text content. For best results, compare similar types of content with consistent formatting.

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