Text & Strings/Text Diff Checker
Text Diff Checker
Compare two text blocks or source files. Spot deletions, additions, and intra-line word edits with zero server upload.
| 1 | function calculateTotal(items, taxRate) { | 1 | function calculateTotal(items, taxRate = 0) { |
| 2 | var total = 0; | 2 | // Use modern reduce syntax |
| 3 | for (var i = 0; i < items.length; i++) { | 3 | const subtotal = items.reduce((sum, item) => sum + item.price, 0); |
| 4 | total = total + items[i].price; | 4 | const tax = subtotal * taxRate; |
| 5 | } | 5 | const grandTotal = subtotal + tax; |
| 6 | if (taxRate > 0) { | 6 | return Number(grandTotal.toFixed(2)); |
| 7 | total = total + (total * taxRate); | ||
| 8 | } | ||
| 9 | return total; | ||
| 10 | } | 7 | } |
How the diff algorithm works
This tool runs a Longest Common Subsequence (LCS) comparison directly inside your browser. It identifies unchanged lines, deleted lines, and newly inserted lines. When a line is modified, intra-line word diffing pinpoints the exact characters or words that changed.
You can toggle between Side-by-Side (split dual-column view) and Unified (single stream view with + and - markers), as well as ignore whitespace and case variations.
FAQ
Is my source code or confidential text private?
Yes, 100%. The diff algorithm executes entirely inside your browser's JavaScript engine. No content is ever sent to a server, logged to an API, or shared.
Can I download a patch file?
Yes. Click the Download .patch button to save a standard Git-compatible unified patch file that can be applied with git apply.
Need to sort, deduplicate, or clean lines before diffing? Try Sort & Dedupe Lines →