Text Diff Checker

Compare two texts and see the differences highlighted. Perfect for code reviews and document comparison.

Original Text

Modified Text

Enter text in both fields to see the differences

How to Use the Text Diff Checker

Paste your original text in the left input field
Paste the modified text in the right input field
View the highlighted differences below
Green lines indicate added content
Red lines indicate removed content
Use the Swap button to switch the texts

Understanding Diff Output

+ Added lines - Lines that appear in the modified text but not in the original
- Removed lines - Lines that were in the original text but removed from the modified version
Unchanged lines - Lines that remain the same in both versions

Common Use Cases

Code review - Compare code changes before and after modifications
Document comparison - Find changes between document versions
Content editing - Track edits made to articles or blog posts
Configuration comparison - Compare config files across environments
Contract review - Identify changes in legal documents
Translation verification - Compare original and translated texts

How It Works

This diff checker uses the Longest Common Subsequence (LCS) algorithm to identify differences between two texts. The algorithm finds the longest sequence of lines that appear in both texts in the same order, then marks lines that are unique to each version as added or removed.

Features

Side-by-side text input for easy comparison
Color-coded diff output (green for additions, red for removals)
Line numbers for easy reference
Statistics showing added, removed, and unchanged lines
Swap button to quickly reverse comparison direction
Works entirely in your browser - no data is sent to any server

Tips for Effective Comparison

Ensure consistent line endings (Unix LF vs Windows CRLF)
Remove trailing whitespace for cleaner comparisons
For large texts, consider comparing smaller sections at a time
Use the line numbers to locate changes in your original files