Text Diff Checker

Compare two texts side-by-side and see differences highlighted. All processing happens in your browser.

Keyboard Shortcuts:

  • Ctrl/Cmd + Enter - Compare texts

Privacy: Text comparison happens entirely in your browser using a longest common subsequence algorithm. No data is sent to any server.

About Text Diff Checking

A diff checker (also known as a text comparison tool) helps you compare two versions of text and identify the differences between them. It's an essential tool for developers, writers, and anyone who needs to track changes between document versions.

Features:

  • Side-by-side text comparison
  • Line-by-line difference highlighting
  • Added, deleted, and modified lines clearly marked
  • Ignore whitespace option
  • Case-insensitive comparison option
  • Swap texts with one click
  • Line numbers for easy reference

Common Use Cases:

  • Compare code changes before committing
  • Review document revisions
  • Check configuration file changes
  • Merge conflict resolution
  • Compare API responses
  • Validate text transformations
  • Track content changes over time

How It Works:

This diff checker uses the Longest Common Subsequence (LCS) algorithm to identify matching lines between the two texts. Lines that don't match are marked as additions, deletions, or modifications. The algorithm efficiently handles texts of various sizes while maintaining accuracy.

Color Legend:

Red (Deleted): Lines that exist in the original text but not in the modified version

Green (Added): Lines that exist in the modified text but not in the original version

Yellow (Modified): Lines that exist in both versions but have different content

Tips for Best Results:

  • Use the "Ignore whitespace" option when comparing code with different indentation
  • Enable "Ignore case" for case-insensitive text comparisons
  • Line numbers help you identify exact locations in your original files
  • The swap button quickly reverses which text is treated as original vs. modified
  • Comparison updates automatically as you type