critica

Critica

A beautiful Git diff viewer for the terminal with split-screen visualization.

Features

• Split-screen diff view: See old and new code side-by-side
• Unified diff view: Traditional unified diff format with -u flag
• Interactive mode: Browse files with fuzzy finder, collapse/expand, and keyboard navigation
• Shows all changes: Displays modified, new/untracked, deleted, and renamed files
• Syntax highlighting: Automatic language detection and syntax highlighting
• Color-coded changes: Red for deletions, green for additions
• Line numbers: Clear line numbering on both sides
• Flexible usage: View diffs for files, directories, or entire repositories
• Git integration: Works with any Git repository

Installation

From Source

go install github.com/danielss-dev/critica@latest

Build Locally

git clone https://github.com/danielss-dev/critica.git
cd critica
go build -o critica

Usage

Basic Usage

# Show diff for entire repository (split-screen view)
critica

# Show diff for a specific file
critica src/main.go

# Show diff for a directory
critica src/

# Show diff in unified format (traditional diff view)
critica --unified

# Interactive mode with fuzzy finder
critica --interactive

# Show staged changes
critica --staged

# Show cached changes (alias for --staged)
critica --cached

# Disable colors
critica --no-color

# Combine flags
critica --interactive --unified

Examples

View all changes in the repository (split-screen):

critica

View changes in unified format:

critica -u

Interactive mode - browse files with fuzzy search:

critica -i

View changes in a specific file:

critica internal/ui/renderer.go

View staged changes before committing:

critica --staged

Configuration

Critica loads optional defaults from ~/.config/critica/config.json (the path provided by os.UserConfigDir()). Example:

{
  "interactive": true,
  "unified": false,
  "no_color": false,
  "diff_mode": "all",
  "diff_style": "filled",
  "added_text_color": "#8df0b5",
  "deleted_text_color": "#ff8ba3"
}

Diff style options

• default – transparent background for unchanged lines with colored gutters
• patch – classic git patch palette without filled backgrounds
• filled – fully colored rows for additions and deletions with a muted neutral background

Color overrides

• added_text_color – six-digit hex color (with or without #) applied to added text and line numbers
• deleted_text_color – six-digit hex color applied to deleted text and line numbers

If omitted, the built-in theme colors are used. Invalid hex values are ignored during config normalization.

Command-line flags always override configuration values.

Interactive Mode

Launch interactive mode with -i or --interactive:

Keybindings:

• ↑/↓ or j/k - Navigate files/lines
• enter - View selected file's diff
• space - Collapse/expand current file
• tab - Toggle between split and unified view
• / - Search/filter files (fuzzy finder)
• esc - Back to file list
• q - Quit

Features:

• Fuzzy file search with filtering
• Collapsible file diffs
• Toggle between split-screen and unified views on the fly
• Keyboard-driven navigation

Command-Line Options

How It Works

Critica uses:

• Cobra for CLI argument parsing
• Bubble Tea for interactive TUI mode
• Bubbles for UI components (list, fuzzy finder)
• Lipgloss for beautiful terminal styling
• Chroma for syntax highlighting
• Git for retrieving diffs

The tool parses Git diff output (including untracked files) and renders it in either:

• Split-screen format: Old code on the left, new code on the right
• Unified format: Traditional diff view with +/- prefixes
• Interactive mode: Browse files with fuzzy search, collapse/expand diffs, and keyboard navigation

Project Structure

critica/
├── main.go                    # Entry point
├── cmd/
│   └── root.go               # CLI commands and flags
├── internal/
│   ├── git/
│   │   └── diff.go           # Git operations (including untracked files)
│   ├── parser/
│   │   └── parser.go         # Diff parser
│   └── ui/
│       ├── renderer.go       # Split-screen & unified rendering
│       ├── interactive.go    # Interactive TUI mode
│       └── theme.go          # Colors and styling
└── README.md

Requirements

• Go 1.24 or higher
• Git installed and in PATH

Makefile

This repository includes a Makefile with common developer targets:

• make build — build the critica binary
• make install — install the package with go install
• make test — run go test ./...
• make lint — run golangci-lint run (requires golangci-lint)
• make fmt — run go fmt ./...
• make vet — run go vet ./...
• make ci — run fmt, vet, lint, and test

Use make or make all to build the binary.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

License

MIT License

Author

Daniel Schwarz (@danielss-dev)