Free Diff Tool Online
Compare two texts with GitHub-style side-by-side or unified diff view.
Paste text above and click Compare to see differences
Key Features
GitHub-Style Display
Side-by-side split view or unified view with line numbers, just like GitHub compare.
Privacy Protected
All processing runs locally in your browser. No data sent to servers.
How to Use Diff Tool
Paste Original Text
Enter the original version of your text in the left input area.
Paste Modified Text
Enter the modified version in the right input area.
Choose View Mode and Compare
Select Unified (single column) or Split (side-by-side) view, then click Compare to see added, removed, and changed lines highlighted with line numbers.
Frequently Asked Questions
Basics
What is a diff?
A diff shows the differences between two versions of text, highlighting what was added, removed, or changed.
What is unified diff format?
Unified diff shows all lines in a single column with +/- markers and line numbers, similar to git diff output. Added lines are shown in green with +, removed lines in red with -.
What is side-by-side diff?
Side-by-side mode shows both texts in two columns with aligned line numbers, similar to GitHub's compare view. This makes it easy to see changes at corresponding positions.
Features
Can I copy the diff result?
Yes, click the Copy button to copy the diff output to your clipboard in standard unified diff format.
Is there a text size limit?
The tool runs entirely in your browser, so the only limit is your browser's memory. It can handle large texts efficiently.