HTML Diff Tool - Compare HTML Documents Online

Compare two HTML documents and highlight differences. View changes in raw or formatted HTML. Line-by-line comparison with statistics. Browser-based and private.

Original HTML

Modified HTML

Format HTML

Ignore whitespace

Show line numbers

Show inline word changes

Differences

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Frequently Asked Questions

The tool compares HTML documents line by line using a Longest Common Subsequence algorithm. It highlights additions (green), deletions (red), and modifications (yellow) with optional inline word-level changes.

Raw comparison preserves original formatting and whitespace. Formatted comparison pretty-prints both documents first, making structural changes easier to spot. Choose based on whether you care about formatting differences.

Yes. Use the 'Format HTML' option to prettify minified HTML before comparison. This makes structural differences visible by adding proper indentation and line breaks.

Green highlights show additions (new content in the second document), red shows deletions (removed from the first), and yellow shows modified lines. With inline changes enabled, word-level differences appear within modified lines.

Yes. All comparison happens locally in your browser using JavaScript. No HTML content is uploaded to any server. Perfect for comparing sensitive HTML files or proprietary templates.

Yes. Enable 'Ignore whitespace' to skip differences caused only by spaces, tabs, or indentation. This is useful when comparing HTML with different formatting styles but identical structure.

When enabled, modified lines show word-by-word differences with color highlights. Added words appear in green, deleted words in red with strikethrough, helping you spot exact text changes within tags.

Yes. Click the 'Copy Diff' button to copy the entire comparison result to your clipboard. This preserves the line-by-line format but not the color highlighting.

Open both HTML files in a text editor, copy the contents, and paste into each input area. Or use your browser's 'View Source' feature to copy HTML from live websites.

The statistics (additions, deletions, modifications, unchanged lines) give you a quick overview of how much has changed between two HTML versions, useful for code reviews and change tracking.

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