git reflog — Recovering Lost Work

The reflog (reference log) records every time a branch tip moves. Even when commits seem "lost" after a reset or rebase, the reflog remembers where you were.

How It Works

Every time HEAD changes — commit, checkout, reset, merge, rebase — Git writes an entry to the reflog:

HEAD@{0}: commit: Add login feature
HEAD@{1}: checkout: moving from main to feature
HEAD@{2}: commit: Fix typo in README
HEAD@{3}: reset: moving to HEAD~2

Basic Commands

git reflog                 # show reflog for HEAD
git reflog show main       # show reflog for a specific branch
git reflog --relative-date # show timestamps instead of indices

The Safety Net

The reflog is your undo button for almost anything in Git. Accidentally deleted a branch? Reset too far back? The commits are still there — the reflog knows where.

Before reset:    A — B — C — D (HEAD)
After reset:     A — B (HEAD)        C — D (still exist!)

The commits C and D aren't gone. They're just unreachable from any branch. The reflog still points to them.

Recovering a Lost Commit

git reflog                     # find the commit hash
git checkout <hash>            # inspect it
git branch recovered <hash>    # create a branch to save it

Or use git reset:

git reset --hard HEAD@{2}     # move HEAD back to reflog entry 2

Try it!

Practice losing and recovering commits:

1. Set up a repo with several commits: git init && echo "first" > file.txt && git add file.txt && git commit -m "First commit"
2. Add a second commit: echo "second" >> file.txt && git add file.txt && git commit -m "Second commit"
3. Add a third commit: echo "third" >> file.txt && git add file.txt && git commit -m "Third commit"
4. Check the log: git log --oneline — you should see three commits
5. Reset back to the first commit: git reset --hard HEAD~2
6. Check the log again: git log --oneline — only one commit remains
7. Use the reflog to find the lost commits: git reflog
8. Recover the third commit: git reset --hard HEAD@{1}
9. Verify recovery: git log --oneline — all three commits are back

Reflog Expiry

Reflog entries don't last forever. By default:

• Reachable entries expire after 90 days
• Unreachable entries expire after 30 days

This means you have at least 30 days to recover lost commits. After that, git gc may clean them up.

When Reflog Saves You

• Accidental git reset --hard
• Deleted a branch with unmerged work
• Bad rebase that lost commits
• Need to find "what did I do yesterday?"