Unified Diff Generator

How to use this developer tool

1. Paste the original text or load a local text file.
2. Adjust the available checks or parsing options.
3. Select Generate Diff or press Ctrl/Cmd + Enter.
4. Review the summary, detailed output, and structured export before using the result.

What this developer tool does

Generate a readable unified diff from two text versions entirely in the browser. Choose the context size and file labels, then copy or download a patch-style result. The implementation uses a line-based longest common subsequence, which keeps ordinary configuration and source edits understandable.

Large files are capped to avoid expensive quadratic comparison in the browser. The generated text is review-oriented and does not include Git object metadata.

Example

The bundled sample demonstrates the expected input. Select Sample, run the analyzer, and compare the detailed output with the summary metrics.

alpha
beta
gamma

Use cases

• Pre-commit and code-review checks
• Query or repository troubleshooting
• Generating copy-ready diagnostics for an issue

Tips for reliable output

• Use the exact text that the target system will receive.
• Keep dialect- or policy-specific options aligned with your project.
• Review warnings even when the main result is valid.
• Save structured JSON when another script needs the findings.
• Confirm destructive operations in the real environment separately.

Processing details

Builds a line-level edit sequence with dynamic programming, groups nearby changes, and emits standard @@ hunk headers.

Large files are capped to avoid expensive quadratic comparison in the browser. The generated text is review-oriented and does not include Git object metadata.