Developer Tools
Text Diff Checker
Compare two texts side by side and see exactly what was added, removed, or changed. Line-by-line diff with color highlighting.
Usage notes
- Green lines = added in the modified text.
- Red lines = removed from the original text.
- Useful for comparing code, configs, documents, and data.
How to Use This Tool
- 1Paste the original text in the left box.
- 2Paste the modified text in the right box.
- 3Click 'Compare' to see the differences highlighted.
Frequently Asked Questions
- What algorithm is used?
- A longest common subsequence (LCS) based diff algorithm that compares text line by line — similar to what Git uses for showing changes.
- Can I compare files?
- Paste the file contents into the text boxes. The tool handles text comparison — for binary files, use a dedicated diff tool.
- Is there a size limit?
- No hard limit, but very large texts (100,000+ lines) may be slow since the diff runs in your browser. For most practical uses, it's instant.
- Is my data sent to a server?
- No. All comparison happens locally in your browser.