Diff Checker
Compare text, code, JSON, and documents side-by-side or inline online. Highlights additions, removals, and statistics 100% locally in your browser.
| Feature | Side-by-Side View | Unified / Inline View |
|---|---|---|
| Layout | Dual column (Original left, Modified right) | Single column with + and - line markers |
| Best For | Visual code reviews, structural comparisons | Git commit patches, exportable .diff files |
| Whitespace & Case Toggles | Supported | Supported |
This tool utilizes a pure Longest Common Subsequence (LCS) diffing algorithm implemented in TypeScript. Text sequences are compared line-by-line or word-by-word while computing exact additions, removals, and unchanged blocks without external dependencies or server roundtrips.
What Does the Diff Checker Do?
Diffing compares two versions of text and highlights exactly what changed — lines added, removed, or modified — the same underlying idea used by version control systems to show what a commit changed.
How to Use the Diff Checker
- Paste the original text on one side and the modified version on the other.
- Choose a side-by-side or unified view.
- Adjust options such as ignoring whitespace or case where relevant.
- Review additions, deletions, and the change statistics.
Technical Notes
- A side-by-side view is often easier for comparing two similar-length documents; a unified view is more compact for reviewing small, localized changes.
- Ignoring whitespace is useful when reformatting (like re-indenting code) would otherwise bury real content changes in noise.
Frequently Asked Questions
Is my confidential code sent to any server?+
No. The comparison algorithm runs 100% locally inside your browser. No data leaves your machine.
What is the maximum supported text size?+
Inputs up to 1 MB per document are supported seamlessly while maintaining smooth browser responsiveness.