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Diff Checker

Compare two texts and see line-by-line differences with color highlighting. Free, private, in-browser.

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Diff Checker

Compare two texts and see line-by-line differences with character-level highlighting.

Original
Modified

How to Use Diff Checker

  1. 1

    Paste your texts

    Paste the original text in the left field and the modified text in the right field.

  2. 2

    Click Compare

    Click the Compare button to generate the diff. Added lines appear in green, removed lines in red, and modified lines show both.

  3. 3

    Review differences

    Scroll through the results. Modified lines show character-level highlighting so you can see exactly what changed within each line.

Frequently Asked Questions

The tool uses a Longest Common Subsequence (LCS) algorithm to find line-by-line differences. For modified lines, it also computes character-level diffs to highlight the exact changes within each line.

Yes. The diff checker works with any text including source code, configuration files, prose, and more. It uses a monospaced font and preserves whitespace for accurate code comparison.

The tool runs in your browser, so performance depends on your device. It handles typical code files and text documents well. Very large files (thousands of lines) may take a moment to process.

No. All comparison is done locally in your browser using JavaScript. No data is sent to any server.