Online Text Diff Checker — Compare Text and Find Differences
What is a Text Diff Checker?
A text diff checker is a tool that compares two pieces of text and highlights the differences between them. It shows what lines have been added, removed, or stayed the same — similar to the git diff command that developers use every day.
Our Text Diff Checker uses the same diff algorithm behind many version control systems. It's perfect for comparing code versions, reviewing document edits, or checking configuration file changes.
Why Use Our Text Diff Checker?
- Git-style diff output — Clear color-coded differences with +/- indicators
- Side-by-side comparison — Paste original and modified text in separate panels
- Line-by-line analysis — Shows which specific lines were added, removed, or unchanged
- 100% private — All comparison happens locally in your browser
How to Use This Text Diff Checker
- Paste the original text in the left textarea
- Paste the modified text in the right textarea
- Click Compare
- View the color-coded diff output with statistics
Understanding the Output
| Color | Meaning |
|---|---|
Green (+) | Lines added in the modified text |
Red (-) | Lines removed from the original text |
| White (no prefix) | Lines that remained unchanged |
Frequently Asked Questions
How does text diff work?
The tool uses a line-by-line comparison algorithm (Myers diff algorithm via the diff npm package). It identifies the minimum number of changes needed to transform the original text into the modified text.
Is my text stored anywhere?
No. All comparison happens in your browser. Your text is never transmitted to any server.
Can I compare code files?
Yes. The diff checker works with any text format: code, configuration files, prose, data, and more.
Is there a limit on text size?
The tool works well with texts up to several thousand lines. For very large files (10,000+ lines), consider using a desktop diff tool instead.