Managing Multiple SSH Keys for Git and GitHub

You use multiple GitHub accounts. You have personal projects and work projects. When you commit code, you want the correct account to show as the author on GitHub.

Your current workflow is painful. You constantly run commands like:

• ssh-add -D ~/.ssh/work-key (remove current key)
• ssh-add ~/.ssh/personal-key (add personal key)

But it doesn’t always work. Even after switching keys, commits still show under the wrong account. This happens because SSH keys and Git author information are separate things.

The Solution

SSH keys authenticate you to GitHub. They prove you have permission to push code. Git configuration sets the commit author. This is what shows up as “Author” on GitHub.

You need to configure both. Here’s how to do it once and forget about it.

Step 1: Configure SSH for Multiple Accounts

Create a ~/.ssh/config file. This file tells SSH which key to use for each GitHub account.

# Create the config file if it doesn't exist
touch ~/.ssh/config
# Open it in your editor
code ~/.ssh/config  # or use nano, vim, etc.

Add this content to the file:

# Personal GitHub account
Host github-personal
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_personal
    IdentitiesOnly yes

# Work GitHub account
Host github-work
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_work
    IdentitiesOnly yes

Important: Replace the IdentityFile paths with your actual SSH key file names.

Step 2: Set Up Git Author Information

Git uses your name and email to set commit authorship. Set this per repository, not globally.

For Personal Projects

cd /path/to/personal/project
git config user.name "Your Name"
git config user.email "your-personal-email@example.com"

For Work Projects

cd /path/to/work/project
git config user.name "Your Name"
git config user.email "your-work-email@company.com"

Tip: Use the same name but different emails. This keeps your GitHub profile consistent while separating personal and work commits.

Step 3: Clone Repositories with Your New Setup

Use your SSH config aliases when cloning repositories.

For personal repositories:

git clone git@github-personal:yourusername/repository-name.git

For work repositories:

git clone git@github-work:company/repository-name.git

What happens: SSH automatically uses the correct key based on the host (github-personal vs github-work).

Alternative: Per-Project SSH Configuration

If you prefer not to use SSH config, set the SSH command per repository:

# For personal projects
cd /path/to/personal/project
git config core.sshCommand "ssh -i ~/.ssh/id_ed25519_personal -F /dev/null"

# For work projects
cd /path/to/work/project
git config core.sshCommand "ssh -i ~/.ssh/id_ed25519_work -F /dev/null"

Verify Everything Works

Check your repository’s Git configuration:

git config --list --local | grep user

Test SSH connections:

ssh -T git@github-personal  # Should show success message
ssh -T git@github-work      # Should show success message

Make a test commit and push. Check GitHub to confirm the correct author shows up.

Common Issues and Solutions

”Permission denied” error

Problem: SSH can’t find or use your key. Solution: Check that your key file path is correct in ~/.ssh/config and that the file has proper permissions (chmod 600 ~/.ssh/key-file).

Wrong author still shows on GitHub

Problem: You set the SSH key but not the Git author information. Solution: Run the git config commands from Step 2 in your repository.

”Host key verification failed” error

Problem: GitHub’s host key isn’t in your known_hosts file. Solution: Connect once manually: ssh -T git@github.com

Already cloned repositories don’t use new SSH config

Problem: Existing repositories don’t automatically use your new SSH aliases. Solution: Update the remote URL:

git remote set-url origin git@github-personal:username/repo.git

Why This Happens

SSH authentication and Git commit authorship work separately:

1. SSH proves who you are to GitHub’s servers
2. Git records who wrote the code in the commit metadata
3. The email in your SSH key comment is just a label — it doesn’t affect Git commits

This separation lets you use one SSH key for multiple Git accounts, or different SSH keys for the same Git account.

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