# Unified Diff & Patch Generator

> Produce a unified diff between two texts that git apply and patch can consume.

A unified diff records the changes between two versions of a file as hunks of context, removed and added lines. This generator computes the longest common subsequence, groups changes into hunks with the context you choose, and emits a patch that both git apply and the patch command accept.

**URL:** https://convertto.tech/t/diff-to-patch
**Category:** Developer Tools (https://convertto.tech/c/developer-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your original.
2. Enter or paste your changed.
3. Enter or paste your file name.
4. Set the context lines.
5. The result appears immediately — copy or download it.

## FAQ

### What is the number in @@ -1,4 +1,5 @@?

The hunk header: the affected lines start at line 1 and span 4 lines in the original, and start at line 1 and span 5 in the new version. It is how patch finds the right place even if surrounding content has shifted.

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