Online Diff Checker

Paste two texts and instantly see what changed. Color-coded line diff highlights additions in green and removals in red.

Line-by-Line Diff
Color-Coded Output
No Data Stored
Original Text (A)
Modified Text (B)

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How the Diff Checker Works

Our online diff checker uses the Longest Common Subsequence (LCS) algorithm — the same core algorithm used by industry-standard tools like Git, GitHub, and diff command-line utilities. It analyzes two texts line by line and produces a precise, color-coded difference report.

Common Use Cases

  • Code Review: Compare two versions of source code before and after a refactor.
  • Document Comparison: Find changes between contract drafts, essays, or reports.
  • Configuration Files: Spot differences between server config files.
  • Content Editing: Track edits made to blog posts, articles, or translated text.
  • Data Validation: Verify that two outputs from different systems match.

Reading the Results

Lines highlighted in green (+) appear only in Text B (added). Lines in red (−) appear only in Text A (removed). Unchanged lines are shown in white for context.