Recovering lost commits with reflog in Git - Commands & Configuration

Introduction

Sometimes you lose track of commits in Git by accident, like after a reset or branch deletion. Git reflog helps you find those lost commits so you can get them back.

When you accidentally reset your branch and lose recent commits.

When you deleted a branch that had commits you want to recover.

When you want to find a commit that is no longer visible in your branch history.

When you want to undo a mistaken git reset or checkout.

When you want to recover work after a rebase or merge gone wrong.

Commands

This command shows a list of recent changes to HEAD, including commits that might be lost from the current branch view.

Terminal

git reflog

Expected Output

a1b2c3d (HEAD -> main) HEAD@{0}: commit: Fix typo in README

f4e5d6c HEAD@{1}: commit: Add user login feature

9a8b7c6 HEAD@{2}: reset: moving to HEAD~2

3d2c1b0 HEAD@{3}: commit: Initial commit

This command checks out the lost commit by its hash from the reflog so you can inspect or recover it.

Terminal

git checkout a1b2c3d

Expected Output

Note: switching to 'a1b2c3d'.



You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches.



HEAD is now at a1b2c3d Fix typo in README

This command creates a new branch at the recovered commit so you can keep it safely and work on it.

Terminal

git branch recovered-commit

Expected Output

No output (command runs silently)

Switch back to your main branch after creating the recovery branch.

Terminal

git checkout main

Expected Output

Switched to branch 'main'

Key Concept

If you lose commits, git reflog lets you find their hashes and recover them even if they are no longer in your branch history.

Common Mistakes

Trying to recover commits without checking reflog first

You won't see lost commits in normal git log, so you might think they are gone forever.

Always run git reflog to find lost commit hashes before giving up.

Not creating a branch after checking out a lost commit

If you stay in detached HEAD state and switch branches, you can lose the recovered commit again.

Create a new branch at the recovered commit to keep it safe.

Summary

Use git reflog to see recent HEAD changes including lost commits.

Checkout the lost commit by its hash from reflog to inspect it.

Create a new branch at the recovered commit to save it.

Switch back to your main branch to continue normal work.

Practice

1. What is the primary purpose of git reflog in Git?

easy

A. To show a log of where HEAD and branch references have been recently

B. To permanently delete commits from the repository

C. To merge two branches automatically

D. To push commits to a remote repository

Solution

1. Step 1: Understand what reflog tracks

   Git reflog records changes to HEAD and branch tips, showing recent commit movements.

2. Step 2: Identify reflog's main use

   It helps find lost commits by listing recent HEAD positions, not deleting or merging.

3. Final Answer:

   To show a log of where HEAD and branch references have been recently -> Option A

4. Quick Check:

   Reflog = recent HEAD changes [OK]

Hint: Reflog shows recent HEAD moves, not branch merges or deletions [OK]

Common Mistakes:

• Confusing reflog with git log
• Thinking reflog deletes commits
• Assuming reflog pushes commits

2. Which command correctly recovers a lost commit using its reflog hash abc1234 by creating a new branch named recovered?

easy

A. git branch recovered && git checkout abc1234

B. git reset --hard recovered abc1234

C. git reflog checkout abc1234 recovered

D. git checkout -b recovered abc1234

Solution

1. Step 1: Understand how to create a branch from a commit hash

   The command git checkout -b <branch> <commit> creates and switches to a new branch at that commit.

2. Step 2: Check each option's correctness

   git checkout -b recovered abc1234 uses correct syntax. git branch recovered && git checkout abc1234 creates branch but checks out commit separately (detached HEAD). git reflog checkout abc1234 recovered is invalid syntax. git reset --hard recovered abc1234 misuses reset.

3. Final Answer:

   git checkout -b recovered abc1234 -> Option D

4. Quick Check:

   Create branch from commit: checkout -b [OK]

Hint: Use 'git checkout -b branch commit' to recover lost commit [OK]

Common Mistakes:

• Using git reflog checkout (invalid command)
• Creating branch and checkout separately causing detached HEAD
• Misusing git reset syntax

3. Given the following reflog output snippet:

abc1234 HEAD@{0}: commit: Fix typo
def5678 HEAD@{1}: commit: Add feature
789abcd HEAD@{2}: commit: Initial commit

What command will restore the commit with message 'Add feature'?

medium

A. git checkout HEAD@{2}

B. git checkout 789abcd

C. git checkout def5678

D. git checkout abc1234

Solution

1. Step 1: Identify the commit hash for 'Add feature'

   From reflog, 'Add feature' commit hash is def5678 at HEAD@{1}.

2. Step 2: Use git checkout with the correct hash

   Checking out def5678 restores that commit state.

3. Final Answer:

   git checkout def5678 -> Option C

4. Quick Check:

   Checkout commit by hash = def5678 [OK]

Hint: Match commit message to hash, then checkout that hash [OK]

Common Mistakes:

• Choosing wrong commit hash
• Using HEAD@{2} which is 'Initial commit'
• Confusing latest commit with target commit

4. You ran git reflog and found a lost commit hash abc1234. You tried git checkout abc1234 but got a detached HEAD warning. How do you fix this to recover the commit safely?

medium

A. Create a new branch at that commit using git checkout -b recovered abc1234

B. Run git reset --hard abc1234 immediately

C. Delete the reflog entry and try again

D. Push the commit hash to remote

Solution

1. Step 1: Understand detached HEAD state

   Checking out a commit hash puts you in detached HEAD, which is risky for new work.

2. Step 2: Create a branch to save the commit safely

   Use git checkout -b recovered abc1234 to create a branch and avoid losing commits.

3. Final Answer:

   Create a new branch at that commit using git checkout -b recovered abc1234 -> Option A

4. Quick Check:

   Fix detached HEAD by creating branch [OK]

Hint: Always create a branch from lost commit to avoid detached HEAD [OK]

Common Mistakes:

• Ignoring detached HEAD and continuing work
• Deleting reflog entries mistakenly
• Trying to push without branch

5. You accidentally reset your branch to an older commit, losing recent commits. You run git reflog and see:

abc1234 HEAD@{0}: reset: moving to abc1234
def5678 HEAD@{1}: commit: Add new feature
789abcd HEAD@{2}: commit: Fix bug

How do you restore your branch to include the lost 'Add new feature' commit?

hard

A. Delete reflog entries before abc1234

B. Run git reset --hard def5678 to move branch back to lost commit

C. Run git checkout abc1234 to stay at reset point

D. Run git merge def5678 from abc1234

Solution

1. Step 1: Identify lost commit hash from reflog

   The lost commit 'Add new feature' is at def5678 (HEAD@{1}).

2. Step 2: Use git reset to move branch pointer back

   Running git reset --hard def5678 restores branch to that commit, recovering lost work.

3. Final Answer:

   Run git reset --hard def5678 to move branch back to lost commit -> Option B

4. Quick Check:

   Reset branch to lost commit hash [OK]

Hint: Use git reset --hard with reflog hash to recover lost commits [OK]

Common Mistakes:

• Checking out reset commit instead of resetting branch
• Deleting reflog entries unnecessarily
• Trying to merge without branch pointer