Undoing Changes

One of Git's greatest gifts is that almost nothing is truly permanent. But "undo" means different things depending on where the change is — uncommitted, committed locally, or already pushed. Using the right tool for each keeps you safe.

A Map of Undo

Match the tool to where the change lives:

Amending the Last Commit

Forgot a file, or made a typo in the message? --amend rewrites the most recent commit:

git add forgotten-file.js
git commit --amend -m "feat: add search with debounce"

reset: Rewrite Local History

git reset moves the current branch pointer to an earlier commit. Its three modes differ in what they do to your files:

git reset --soft HEAD~1    # undo commit, KEEP changes staged
git reset --mixed HEAD~1   # undo commit, keep changes unstaged (default)
git reset --hard HEAD~1    # undo commit AND discard the changes (destructive!)

--soft   → commit undone, work back in staging
--mixed  → commit undone, work back in working dir
--hard   → commit undone, work gone

--soft is great for "I committed too early" — it puts your work back in staging so you can recommit. --hard throws the work away, so use it only when you're sure.

revert: Undo Safely in Shared History

reset rewrites history, which is dangerous for commits others already have. For anything pushed, use git revert instead. It doesn't erase the commit — it creates a new commit that undoes the changes:

git revert a1b2c3d

before:  A ─ B ─ C(bug)
after:   A ─ B ─ C(bug) ─ D(undoes C)

History stays intact and honest; everyone can pull the revert cleanly. Rule of thumb: reset for local, revert for pushed.

reflog: Your Safety Net

Think you lost commits after a bad reset? The reflog records where HEAD has been, even for commits no longer on any branch:

git reflog

a1b2c3d HEAD@{0}: reset: moving to HEAD~1
f9e8d7c HEAD@{1}: commit: the work I thought I lost

Recover by pointing a branch back at that SHA:

git reset --hard f9e8d7c   # or: git switch -c recovered f9e8d7c

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