diff
compare
text
code
Updated 2026-02-14
Diff Checker
Compare two texts side-by-side with line, word, or character-level highlighting.
Tool Area
Instant client-side processing
Mode
A
Original Text
Source
B
Modified Text
Target
## Compare Text Differences Instantly
Tracking changes between two versions of a document or code snippet can be a nightmare. The **Diff Checker** visualizes every addition, deletion, and modification, saving you from manual line-by-line inspection.
### How It Works
We use a difference algorithm to compute the minimum number of edits required to transform "Text A" into "Text B".
- **Green**: Added lines/words.
- **Red**: Deleted lines/words.
- **Grey**: Unchanged context.
### Comparison Modes
1. **Line-by-Line**: Best for code (JavaScript, Python) and lists.
2. **Word-by-Word**: Best for articles, essays, and emails.
3. **Character-by-Character**: Best for spotting typos or small data changes (e.g., API keys).
### Use Cases
- **Code Review**: Check what changed before committing to Git.
- **SEO**: Compare an old article with a new draft.
- **Legal**: Verify that a contract matches the original template.
- **Plagiarism**: Compare student work against a source.
Common Questions
QIs my code safe?
Yes. All comparison logic runs in your browser. Your proprietary code or sensitive documents are never uploaded to our servers.
QWhat's the difference between the modes?
Line mode compares full lines (good for code). Word mode compares text (good for essays). Character mode highlights every typo.
QDoes it support huge files?
It works best for files under 1MB. Larger files might slow down your browser since it parses the diff locally.
QCan I ignore whitespace?
Yes, use the 'Ignore Whitespace' toggle to see substantive changes only.