Codiff

Codiff is an open-source desktop application built by nkzw-tech that provides a fast, local diff viewer for Git repositories. Written in TypeScript and distributed under the MIT License, it lets developers review staged and unstaged changes before committing, with optional LLM-assisted walkthroughs powered by the Codex CLI.

What It Is

Codiff is a native desktop diff viewer that runs locally against any Git repository. It sits between a developer's editor and their commit workflow, offering a clean visual interface for reviewing changes. Unlike web-based code review tools, Codiff operates entirely on the local machine — no server, no account, no network round-trip required. The tool is installable via Homebrew on macOS and distributed as a downloadable app through GitHub Releases.

Core Workflow

Codiff integrates into the terminal-first Git workflow through a companion CLI command installed via Codiff > Install Terminal Helper. From any Git repository directory, running codiff opens a native window showing current diffs. Developers can also:

• Pass a specific repository path: codiff /path/to/repository
• Review a specific commit by hash: codiff a1b2c3d
• Open multiple repositories simultaneously, each in its own native window
• Run codiff -w to trigger an LLM-generated walkthrough order via Codex

LLM Walkthrough Feature

The -w flag integrates with the local Codex CLI to generate a suggested review order and additional context for the changes in a repository. Codiff looks for Codex on PATH, /opt/homebrew/bin/codex, and /usr/local/bin/codex. For non-standard Codex install locations, the CODIFF_CODEX_PATH environment variable can point to the binary. This feature requires Codex to be installed and verified separately before use.

Inline Review Comments

Codiff supports commenting directly on changed lines within the diff view. All review comments can be copied as Markdown, making it straightforward to carry notes into pull request descriptions, commit messages, or follow-up documentation.

Update: v0.4.0

The latest release is v0.4.0, published on May 20, 2026. The repository was created on May 15, 2026, and has accumulated over 400 stars and 16 forks within days of launch, according to the GitHub repository metadata. Active development is ongoing, with the last push recorded on May 20, 2026. The project is built with TypeScript and uses a Vite/Electron stack based on the development commands in the repository.