Text Diff Checker

Compare two texts and see exactly what changed. Line-by-line diff with added/removed highlighting. All processing in your browser.

Original1 lines
Modified1 lines

Line-by-Line Comparison

Uses the Myers diff algorithm to produce minimal, accurate diffs between any two text inputs.

Code & Text Support

Works with source code, configuration files, markdown, plain text, JSON, and any other line-based content.

Instant Diff, No Upload

All comparison happens locally in your browser. Your files are never sent to a server.

Diff Statistics

See at a glance how many lines were added, removed, and unchanged.

How to Use the Text Diff Checker

  1. 1.Paste your original text into the left panel.
  2. 2.Paste your modified text into the right panel.
  3. 3.The diff updates automatically — green lines are additions, red lines are deletions.
  4. 4.Toggle "Show unchanged lines" to focus only on changes.

Frequently Asked Questions

What diff algorithm does this use?

This tool uses the Myers diff algorithm, the same algorithm used by Git.

Can I compare code files?

Yes — paste the content of any text-based file: source code, JSON, YAML, Markdown, HTML, CSS, etc.

Is my data private?

Completely. All processing runs in your browser. Nothing is uploaded to any server.

What do the colors mean?

Green lines (+) are additions. Red lines (-) are deletions. Neutral lines are unchanged.