Skip to main content
The Text Diff Checker utility helps you identify differences between two versions of text. It provides both line-level and word-level comparison modes, making it easy to track changes in documents, code, or any text content.

​
Features

​
Comparison modes

Choose between two comparison modes based on your needs: Line Diff: Compares text line by line, perfect for:
  • Reviewing code changes
  • Comparing configuration files
  • Analyzing document revisions
  • Tracking multi-line text modifications
Word Diff: Compares text word by word, ideal for:
  • Reviewing sentence changes
  • Comparing short text snippets
  • Identifying small edits in paragraphs
  • Analyzing single-line modifications
Use Line Diff for structured content like code or configuration files. Use Word Diff for prose, documentation, or single-line comparisons.

​
Visual difference highlighting

The utility displays differences with clear color-coded highlighting:
  • Green background: Added content (present in modified text, absent in original)
  • Red background: Removed content (present in original text, absent in modified)
  • White background: Unchanged content (identical in both versions)
Each line in the diff output includes a prefix:
  • + for added lines/words
  • - for removed lines/words
  • (two spaces) for unchanged lines/words

​
Use cases

​
Code review

Compare different versions of source code to understand what changed: 
// Original
function calculateTotal(price, tax) {
  return price + tax;
}

// Modified
function calculateTotal(price, tax, discount) {
  return price + tax - discount;
}
The diff will highlight the added discount parameter and the modified return statement.

​
Document comparison

Track changes in documentation, articles, or any text content:
  • Compare draft versions
  • Review editorial changes
  • Verify translations
  • Check content updates
The diff algorithm used is the Myers diff algorithm, which is the same algorithm used by Git for showing file changes.

​
Configuration validation

Compare configuration files to ensure correct settings:
  • Review environment-specific configs
  • Verify deployment configurations
  • Compare backup and production settings
  • Audit configuration changes

​
Data verification

Validate data transformations or migrations:
  • Compare JSON/XML before and after transformation
  • Verify data format conversions
  • Check API response changes
  • Validate data cleaning operations
Both text areas support multi-line input. Press Cmd/Ctrl+Enter to trigger the comparison, or Cmd/Ctrl+K to clear all fields.

​
Understanding the diff output

​
Line diff format

In line diff mode, each line is compared independently: 
  Line that exists in both versions
- Line that was removed from the original
+ Line that was added in the modified version
  Another unchanged line

​
Word diff format

In word diff mode, changes within lines are highlighted at the word level: 
The quick brown fox jumps
The quick red fox runs
Will show “brown” in red (removed) and “red” in green (added), along with “jumps” in red and “runs” in green.

​
Empty lines and whitespace

The diff checker preserves:
  • Empty lines in the original text
  • Leading and trailing whitespace
  • Multiple consecutive spaces
This makes it suitable for comparing code where whitespace matters.
Line diff compares entire lines as units. A small change in a long line will mark the entire line as different. Use word diff for more granular comparison.

Build docs developers (and LLMs) love

Get started for freeTalk to us