Diff Checker

🔒 Processed locally in your browser

4.9(222)

Compare two blocks of text or code side-by-side to find differences, added lines, and removed lines. Fast, private line-by-line diff with patch export.

Original (Base Text)7 lines

Modified (New Text)5 lines

Line Comparison Output

+4 additions•-6 deletions•1 unchanged

-1function calculateTotal(items) {

-2 let sum = 0;

-3 for (let i = 0; i < items.length; i++) {

-4 sum += items[i].price;

-5 }

-6 return sum;

+1function calculateTotal(items, discountRate = 0) {

+2 const subtotal = items.reduce((acc, item) => acc + item.price, 0);

+3 const discount = subtotal * discountRate;

+4 return Math.max(0, subtotal - discount);

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About Diff Checker

Compare source code, documents, or revisions side-by-side. Highlights exact line additions, deletions, and unchanged segments using the Longest Common Subsequence algorithm.

How to Use Diff Checker

1Paste your original base text into the left pane
2Paste your revised or modified text into the right pane
3Inspect highlighted additions (+ in green) and deletions (- in red)
4Copy the unified patch with line markers

Examples & Calculations

Detecting refactored JavaScript / TypeScript functions

Checking revisions between legal agreements or essay drafts

Frequently Asked Questions

How does the diff algorithm work?▼

It computes line-by-line differences using the Longest Common Subsequence (LCS) dynamic programming algorithm.

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