Git → JJ Quick Reference

If you’re coming from Git, this page is your quick reference for the differences that matter most. For the full conceptual explanation, see the Mental Model guide.

Command Comparison

Git	JJ	Notes
git status	jj status	Same concept
git diff	jj diff	Same concept
git log	jj log	JJ shows graph by default
git add && git commit	jj describe && jj new	No staging needed
git commit --amend	(automatic)	Working copy always amends
git checkout -b	jj new	Branches optional
git checkout	jj edit	Edit any commit
git rebase -i	jj rebase / jj squash	Simpler commands
git stash	(not needed)	Just jj new
git cherry-pick	jj duplicate	Copy commits
git reset --hard	jj undo	Safer recovery

Key Differences

Concept	Git	JJ
Working copy	Prepares a future commit	Is the commit
Staging area	Explicit git add	None — automatic
Commits	Immutable	Mutable by default
Branches	Required, auto-follow	Optional “bookmarks,” manual
Conflicts	Block workflow	First-class data — details
Undo	Limited git reflog	Full operation log
History editing	Dangerous rebase -i	Safe — descendants rebase automatically

The Operation Log vs Git Reflog

Git Reflog	JJ Operation Log
Tracks HEAD movements only	Tracks every repository change
Separate reflog per branch	One unified history
Entries expire (90 days)	Permanent history
Hard to understand	Clear command history
Can’t restore complex states	Full state restoration

See the Operation Log guide for the full reference.

Revsets for Querying History

JJ has a powerful query language called “revsets” for selecting commits:

jj log -r "trunk..@"      # Commits between trunk and here
jj log -r "mine()"        # Your commits
jj log -r "stack"         # Current stack (LazyJJ alias)
jj rebase -s "stack" -d trunk   # Rebase entire stack

Common Git User Confusions

“Where’s git stash?” → Not needed. Your current commit already has your work. Just jj edit <other-commit> to switch contexts. Return with jj edit <original> and your work is still there.

“How do I stage files?” → You don’t. Working copy is the commit. Files are automatically included. To split changes later, use jj split.

“Why didn’t my bookmark move?” → JJ bookmarks don’t auto-follow like Git branches. You must manually jj bookmark set <name>. See Common Mistakes for details.

“How do I amend a commit?” → Just edit files. Your working copy always amends the current commit. To edit an older commit, use jj edit <change-id>.

Next Steps

• Mental Model — Full explanation of JJ’s conceptual shifts
• Quick Start — Get productive in 5 minutes
• Common Mistakes — Avoid the common pitfalls