Diff Checker

Compare texts side-by-side with highlighted differences

Free to use

Developer

Original Text

Modified Text

Ignore whitespace

About Diff Checker

Diff Checker is a powerful side-by-side text comparison tool that instantly highlights differences between two documents or code snippets. Whether you are reviewing code changes, comparing document versions, or tracking content modifications, Diff Checker makes it easy to spot what is changed at a glance.

Built entirely in your browser with zero server uploads, Diff Checker processes everything locally on your device for maximum privacy and speed. Perfect for developers, writers, and anyone who needs to understand exactly what changed between two versions of text.

Local only

Privacy-safe

Instant

Real-time comparison

No limits

Compare any size

100% free

Always available

How to use Diff Checker

Paste Your Texts

Enter or paste the original text in the left panel and the modified text in the right panel.

View the Diff

Differences are highlighted automatically in real-time as you type or paste.

Export or Share

Download the comparison report, copy results, or share the analysis with others.

Pro Tips

Use the unified diff view to see changes in context format, perfect for code reviews and technical documentation.
Try uploading files directly to compare entire documents without manually copying and pasting.
Toggle between light and dark mode to reduce eye strain during long comparison sessions.
Bookmark your comparisons using the browser's native tools to reference changes later without re-uploading.