Compare two texts line by line and find differences with added, removed, and changed highlights, all processing happens in your browser
Text Tools
About This Tool
Diff Checker is a browser-based tool that compares two texts line by line using the Longest Common Subsequence (LCS) algorithm. It identifies added, removed, and changed lines with color-coded highlights and line numbers, provides statistics on differences, and supports one-click copy of results — all processing happens locally in your browser with zero server dependency.
Key Features
- LCS-based line-by-line diff algorithm for accurate comparison
- Color-coded highlights for added (green), removed (red), and changed lines
- Side-by-side original and modified text input panels
- Statistics showing count of added, removed, and changed lines
- Line numbers displayed for easy reference in diff output
- One-click copy of diff results and clear all functionality
Use Cases
- Compare document revisions to track what changed between versions
- Review code changes before committing or merging branches
- Check configuration file differences across environments
- Verify text modifications in legal or contract documents
- Compare API responses or data outputs for regression testing
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Frequently Asked Questions
How does the Diff Checker compare texts?
The tool uses the Longest Common Subsequence (LCS) algorithm to compute line-by-line differences. It identifies added, removed, and changed lines, then displays them with color-coded highlights and line numbers.
What do the added, removed, and changed statistics mean?
Added lines are present only in the modified text, removed lines exist only in the original text, and changed lines are pairs where a line was removed from the original and replaced with a different line in the modified text.
Can I copy the diff results?
Yes, after comparing texts a Copy button appears that lets you copy the entire diff output to your clipboard, including line numbers and change indicators.
Is my data safe when using this tool?
Absolutely. All text comparison happens locally in your browser. No data is uploaded to any server, ensuring your information remains completely private and secure.
Can I use this tool on my phone?
Yes, the Diff Checker is fully responsive and works on all devices including smartphones, tablets, and desktop computers.