Diff Checker — Text Compare Tool

How to Use This Diff Checker

1. Paste the original text in the left panel
2. Paste the modified text in the right panel
3. Differences are highlighted instantly — green for additions, red for deletions
4. Use options to ignore whitespace or case differences
5. Click Copy Diff to copy the unified diff output

Features

• Line-by-Line Diff — See exactly which lines were added, removed, or unchanged
• Dual Line Numbers — Left and right line numbers for easy navigation
• Ignore Whitespace — Toggle to ignore leading/trailing whitespace differences
• Ignore Case — Toggle to make comparison case-insensitive
• Swap Texts — Quickly swap original and modified texts
• Copy Diff — Copy the diff in standard unified format

Frequently Asked Questions

Is my data safe?

Yes. All comparisons are done entirely in your browser. No text is sent to any server.

Can I compare code files?

Yes. This tool works with any text including source code. It performs a line-by-line comparison using an LCS (Longest Common Subsequence) algorithm.

Is there a size limit?

There is no hard limit, but very large texts (100,000+ lines) may slow down your browser since the diff is computed client-side.