diff2html

Generate GitHub-style HTML diff views from git diff output or commit hashes. Each file's diff is shown as a collapsible section with syntax highlighting, making it easy to navigate large changes.

Example:

What GitHub shows:

Usage

# Diff current branch against its gh stack parent, or main/master when not stacked
python diff2html.py

# Diff current branch against a specific branch
python diff2html.py -b main

# Specify a commit (compare commit..HEAD)
python diff2html.py abc123def

# From a diff file
python diff2html.py diff.patch

# From stdin
git diff HEAD~3 HEAD | python diff2html.py --stdin

# Custom output file
python diff2html.py -o review.html

Options

Argument	Description
source	Commit hash, diff file path, or omit to diff current branch against its gh stack parent or main/master
-b, --branch	Compare current branch against the given branch (e.g. -b main)
-o, --output	Output HTML file (default: diff.html)
--stdin	Read diff from stdin

Features

• File-based view — each changed file is a collapsible <details> panel with a copy-path button
• File list — summary of all changed files with add/del counts; click to jump
• Sidebar tree — directory tree with file status and stats for quick navigation
• Expand / collapse all — toggle all files at once
• Syntax highlighting — source code in diffs is highlighted via pygments (auto-detected from file extension), with GitHub-style token colors
• GitHub-style light theme — inline CSS, no external dependencies
• Commit metadata — shows title, author, date when diffing against a branch or commit
• gh stack support — automatically compares a stacked branch with the layer immediately below it; explicit -b/--branch takes precedence
• No external runtime dependencies — pure Python standard library; pygments is optional but recommended
• WSL support — auto-detects WSL2 and prints a file://wsl$/... URL for Windows browser

Requirements

• Python 3.10+
• pygments (optional, for syntax highlighting) — pip install pygments