What this tool does
Compare two code snippets and see the differences highlighted. Perfect for code reviews, comparing versions, and understanding changes. All processing happens locally in your browser.
Familiar diff highlighting
Green highlights for new lines
Red highlights for removed lines
Split or unified diff view
Original
Modified
Ready to Compare
Enter your original and modified code above, then click Compare to see the differences.
Tips
About Code Diff Tool
Compare two code snippets and visualize the differences with our free online code diff tool. Features GitHub-style highlighting with green for additions and red for deletions. Choose between side-by-side (split) view or unified diff view. See line numbers, statistics on changes, and export diffs as unified patch files. Perfect for code reviews, comparing versions, debugging changes, and understanding modifications. Supports any text or code language. All processing happens locally in your browser - your code never leaves your device.
Understanding Diff Output
Additions (+)
Lines highlighted in green with a + prefix are new content that was added in the modified version.
Deletions (-)
Lines highlighted in red with a - prefix are content that was removed from the original version.
Context Lines
Unchanged lines provide context around the changes, helping you understand where modifications occurred.
View Modes
Split View
Shows original and modified code side-by-side in separate columns. Best for comparing corresponding lines and seeing exactly what changed at each position.
Unified View
Shows all changes in a single column with additions and deletions interleaved. Similar to git diff output, compact and efficient for scanning changes.
Common Use Cases
- Code Review - Compare code changes before merging or committing to understand what was modified
- Debugging - Compare working code with broken code to identify the change that introduced a bug
- Learning - Compare your solution with a reference implementation to understand different approaches
- Version Comparison - Compare different versions of configuration files or scripts
- Merge Conflicts - Understand conflicting changes when resolving merge conflicts
- Documentation - Create patch files to document and share specific changes
Frequently Asked Questions
What is a code diff?
A code diff (or diff) shows the differences between two versions of text or code. It highlights what was added, removed, or changed, making it easy to see modifications at a glance.
What do the colors mean?
Green lines with + indicate additions (new content). Red lines with - indicate deletions (removed content). Gray/white lines show unchanged context.
What is a unified diff patch file?
A unified diff patch file is a standard format that records differences between files. It can be used with git, the patch command, and other tools to apply changes to files.
Can I use this for any programming language?
Yes! The diff tool works with any text, including all programming languages, configuration files, markdown, and plain text. The comparison is line-based and language-agnostic.
Is my code safe when using this tool?
Absolutely! All comparison and diff generation happens entirely in your browser using JavaScript. Your code is never sent to any server, ensuring complete privacy.
What is the difference between Split and Unified view?
Split view shows original and modified side-by-side in separate columns. Unified view shows all changes in a single column with additions and deletions interleaved, similar to git diff output.