How to fix fatal: A branch named 'feature' already exists in Git

If you simply want to work on the branch that already exists, switch to it without the -b flag:

# Modern Git (2.23+)
git switch feature

# Or using checkout
git checkout feature

The -b flag tells Git to create a new branch. If the branch already exists, you don't need it - just switch directly.

Check what branches exist locally to understand the situation:

# List local branches
git branch

# List all branches (local and remote)
git branch -a

# List branches with last commit info
git branch -v

Look for your branch name in the output. If it's there, you can switch to it or decide whether to delete it.

If you need a new branch and want to keep the existing one, use a different name:

# Use a more specific name
git checkout -b feature-v2
git checkout -b feature-login-refactor
git checkout -b feature-2024-12

# Or append a number/date
git checkout -b feature-$(date +%Y%m%d)

Consider adopting a naming convention that includes ticket numbers or dates to avoid collisions.

If you don't need the existing branch, delete it before creating the new one:

# Safe delete (only if merged)
git branch -d feature

# Force delete (even if not merged - use with caution)
git branch -D feature

# Then create your new branch
git checkout -b feature

Warning: -D (force delete) will permanently remove the branch and any unmerged commits. Make sure you don't need those commits first.

Use the uppercase -B flag to reset an existing branch to a new starting point:

# Reset 'feature' to current HEAD and switch to it
git checkout -B feature

# Reset 'feature' to a specific commit/branch
git checkout -B feature main
git checkout -B feature origin/main

# Modern equivalent with git switch
git switch -C feature
git switch -C feature main

The -B flag creates the branch if it doesn't exist, or resets it if it does. This is useful when you want to start fresh from a different point.

If you want to track a remote branch that has the same name as an existing local branch:

# Option 1: Delete local and checkout fresh from remote
git branch -D feature
git checkout feature  # Will auto-track origin/feature

# Option 2: Reset local branch to match remote
git checkout feature
git reset --hard origin/feature

# Option 3: Use -B to reset and track
git checkout -B feature origin/feature

This is common when a remote branch was deleted and recreated, but your local branch still references the old version.