jj diff

jj diff

Usage

jj diff [OPTIONS] [PATHS]...

Shows differences in files between revisions.

IMPORTANT: Always use the --git flag when running jj diff. The default diff output format is not reliably parseable. The --git flag produces standard Git-format diffs that are well-understood.

Common Options

• -r, --revision <REVSET> - Show changes in this revision (compare with parent)
• --from <REVSET> - Start revision for comparison
• --to <REVSET> - End revision for comparison (default: @)
• -s, --summary - Show only file names, not content diff
• --stat - Show a histogram of changes
• --git - REQUIRED. Show Git-format diff
• --color-words - Show word-level diff with colors
• --tool <TOOL> - Use external diff tool

Common Patterns

# Show changes in working copy (vs parent)
jj diff --git

# Show changes in a specific revision
jj diff --git -r @-

# Compare two revisions
jj diff --git --from main --to @

# Show only which files changed
jj diff -s

# Show diff for specific file
jj diff --git src/lib.rs

# Show changes between trunk and working copy
jj diff --git --from trunk() --to @

# Use external diff tool
jj diff --tool meld

Understanding Revision Comparison

• jj diff alone shows @- → @ (parent to working copy)
• jj diff -r X shows changes introduced BY revision X (its parent → X)
• jj diff --from A --to B shows A → B

Guidelines

Always use --git flag for machine-readable output. For large diffs, consider using -s first to get a summary, then showing specific files.