Dev Tools/Diff Checker
Diff Checker
Compare two texts and highlight the differences
Original Text
Modified Text
Differences
+ 0 Added- 0 Removed1 Unchanged
1
Text Diff Checker Guide
Learn how to compare texts and identify differences
What is Diff Checking?
Diff checking compares two pieces of text line by line to identify additions, deletions, and unchanged content. It's commonly used for code reviews, document comparison, and tracking changes in text files.
How to Use This Tool
- Paste the original text in the left field
- Paste the modified text in the right field
- View the highlighted differences below
- Green highlights show additions, red shows deletions
Pro Tips
- Use the swap button to reverse the comparison direction
- The comparison is case-sensitive by default
- Large texts may take a moment to process
Browser Support
This diff checker works in all modern browsers. All processing happens locally in your browser - your text is never sent to any server.
Frequently Asked Questions
What diff algorithm does this tool use?
This tool uses a line-by-line comparison algorithm. It compares each line sequentially, marking lines as added (green), removed (red), or unchanged. For character-level differences within changed lines, more sophisticated algorithms like Myers diff may be needed.
Why does it show a line as both removed and added?
When a line is modified (not just added or removed), the tool shows the old version as 'removed' and the new version as 'added'. This helps you see exactly what changed, even if it's just a small part of the line.
Can I compare files instead of text?
This tool works with text pasted into the input fields. To compare files, open them in a text editor, copy their contents, and paste into the Original and Modified fields. For file comparison with syntax highlighting, consider using tools like VS Code's built-in diff viewer.
Is the comparison case-sensitive?
Yes, the comparison is case-sensitive by default. 'Hello' and 'hello' will be shown as different. If you need case-insensitive comparison, convert both texts to the same case before comparing.
Why are whitespace-only changes highlighted?
The tool compares exact character sequences, including whitespace. Trailing spaces, different line endings (\r\n vs \n), or tabs vs spaces will be detected as differences. This is important for code where whitespace matters.