Diff Checker

// compare two texts · highlight added · removed · unchanged lines · nothing leaves your browser

original text
modified text
diff result

What is a diff checker?

A diff checker compares two versions of text and highlights what changed — lines added, removed, or unchanged. It's essential for code reviews, comparing document versions, spotting API response changes, or verifying that a refactor didn't accidentally change logic.

How to use this tool

  • Paste your original text in the left panel
  • Paste the modified text in the right panel
  • Click Compare to see the diff
  • Green lines were added, red lines were removed
  • Gray lines are unchanged

Frequently Asked Questions

Does this work for code?+
Yes — paste any code, JSON, config files, or plain text. The diff is line-based so it works the same regardless of whether you're comparing prose, Python, YAML, or SQL.
Is my text kept private?+
Yes. All comparison happens in your browser using JavaScript. Nothing is sent to any server. This makes it safe to compare sensitive config files, private documents, or proprietary code.