Diff Checker

Compare two texts side-by-side and see exactly what changed, with word-level hig...

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Quick answer

A diff checker compares two blocks of text and highlights what changed between them. YaliKit's version runs a Longest Common Subsequence algorithm entirely in your browser to line up the texts side by side, then highlights the exact words that differ within each line, with options to ignore whitespace or case.

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Comparison Features

LCS Algorithm - Uses Longest Common Subsequence for accurate diff results
Line Numbers - Dual line numbers for both original and modified versions
Ignore Whitespace - Skip indentation and trailing space differences
Ignore Case - Case-insensitive comparison option
Swap & Sample - Quick swap texts or load sample code for testing
Change Stats - See counts of added, removed, and unchanged lines

Why Use Diff Checker?

Side-by-Side, Word-Level

See the two texts side-by-side and (the part most tools miss) exactly which words changed within a line are highlighted, not just the whole line. Switch to a unified view any time.

Instant, As You Type

The diff updates live the moment you paste or edit, no 'compare' button to hunt for.

Ignore Whitespace or Case

One click to skip indentation or capitalisation differences, perfect for comparing code with different formatting.

Color Coded Results

Green for additions, red for deletions, with clear visual indicators. Understand changes at a glance.

100% Private

All processing happens in your browser. Your text data never leaves your device or gets stored anywhere.

Common Uses for Diff Checker

Code Review

Compare code versions to review changes before merging or deploying.

Document Revision

Track changes between document drafts and identify what was modified.

Merge Conflicts

Understand and resolve merge conflicts by comparing conflicting versions.

Config Comparison

Compare configuration files between environments to spot differences.

How It Works

1

Paste Your Texts

Enter the original text in the left box and the modified version in the right box. You can compare code, documents, or any text content.

2

Configure Options

Use "Ignore whitespace" to skip indentation differences or "Ignore case" for case-insensitive comparison.

3

Review Differences

See the color-coded diff result below. Green lines are additions, red lines are deletions, and white lines are unchanged.

Tips for Better Comparisons

Use Load Sample

Click 'Load Sample' to see how the diff checker works with a real code example before using your own text.

Ignore Whitespace for Code

When comparing code from different editors or formatters, enable 'Ignore whitespace' to focus on actual content changes.

Large Files

For very large files (10,000+ lines), the comparison may take a moment. Consider breaking large comparisons into smaller sections.

Frequently Asked Questions

Paste the original on the left and the changed version on the right. The diff appears instantly below. In Split view the two are shown in parallel columns, and the exact words that changed inside each line are highlighted (red on the left, green on the right), so you can see precisely what changed rather than just which whole lines differ. Toggle to Unified view for a single combined column with + / - markers.
It uses the Longest Common Subsequence (LCS) algorithm at the line level to find added, removed and unchanged lines, then runs a second word-level LCS on changed lines to highlight the specific words that differ.
Yes, the diff checker is perfect for comparing code. It preserves formatting and shows syntax-aware differences. Use the 'Ignore whitespace' option when comparing code with different indentation styles.
No, all comparison happens directly in your browser using JavaScript. Your text never leaves your device, ensuring complete privacy. When you close the page, all data is gone.
When enabled, the diff checker trims whitespace from the beginning and end of each line before comparing. This is useful when comparing code that has different indentation styles but is otherwise identical.
Yes! Click the Swap button to exchange the original and modified texts. This is useful to see the diff from the other direction.
Since processing happens in your browser, there's no server-side limit. Very large texts (10,000+ lines) may take a moment depending on your device.
Yes. For structured data, the JSON Compare tool understands JSON objects and can ignore key/array order. This diff checker is best for plain text, code, prose, config files and logs.

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