diff

Git · Reference cheat sheet

📋 Overview

git diff shows changes between worktree, index, commits, and branches. Use it before staging/committing and in code review. Word-diff and path filters help focus on signal.

🔧 Core concepts

• Unstaged — git diff (worktree vs index).
• Staged — git diff --staged / --cached (index vs HEAD).
• Commits — git diff A B, git diff A..B, A...B (merge-base).
• Stats — --stat, --numstat, --name-only.
• Options — -w ignore whitespace; --word-diff; -M renames.

💡 Examples

git diff
git diff --staged
git diff HEAD
git diff main...feature --stat

git diff abcdef1 1234567 -- apps/web
git diff --name-only origin/main

# Word / whitespace
git diff --word-diff
git diff -w

# Function context (C/JS often)
git diff -W

# Binary detection
git diff --binary

# Exit code for scripts (0 = no diff)
git diff --quiet || echo "dirty"

⚠️ Pitfalls

• A..B vs A...B differ for branch comparison — ... uses merge-base (PR-style).
• Line endings / CRLF can create noisy diffs — normalize with .gitattributes.
• Generated files and lockfile churn drown real changes — pathspec filter.
• diff of binary shows “Binary files differ” — use Git LFS or external tools.
• Submodule diffs show SHA changes only unless you diff inside the submodule.

🔗 Related

• status.md
• stage.md
• log.md
• blame.md
• gitattributes.md
• commit.md