How to Use Multiple GitHub Accounts with Different SSH Keys

Note: If you’re new to SSH, please check out my latest post Complete SSH Key Beginner’s Guide , which is more beginner-friendly and comprehensive. This article has more detailed information for those interested in specifics.

If you’re working with multiple GitHub accounts, you might want to keep your credentials separate for each account. This tutorial will show you how to use different SSH keys for two GitHub accounts (account1 and account2) on the same machine.

🛠️ Step 1: Generate SSH Keys for Both Accounts

First, generate SSH keys for each account. If you already have one key for account1, you’ll generate a separate key for account2.

Generate Key for Account 1:（If you haven’t done so already） For account1, generate an SSH key:

ssh-keygen -t ed25519 -C "your_email2@example.com" -f ~/.ssh/id_ed25519_account1

Note:

• ssh-keygen is used to generate an SSH key pair.
• -t ed25519: Uses the ed25519 algorithm, which is faster and more secure than rsa.
• -C "your_email1@example.com": Adds a comment (e.g. your email) for identification purposes.
• -f ~/.ssh/id_rsa_account1: Specifies the file where the private key will be saved.

Generate Key for Account 2:
Similarly, generate a separate SSH key for account2:

ssh-keygen -t ed25519 -C "your_email2@example.com" -f ~/.ssh/id_ed25519_account1

After creating these keys, make sure to add their corresponding public keys (id_rsa_account1.pub and id_rsa_account2.pub) to the respective GitHub account’s SSH settings.

Add to GitHub
After generating the keys, open each public key file (id_ed25519_account1.pub and id_ed25519_account2.pub) in a text editor, copy the full contents, and paste it into the corresponding GitHub account’s SSH keys settings under:

GitHub → Settings → SSH and GPG Keys → New SSH key

⚙️ Step 2: Configure SSH config File

Next, we’ll configure the SSH settings to ensure that each account uses the correct key.

Open your terminal and edit the SSH config file:

nano ~/.ssh/config

Add the following configuration:

# Account 1 - Default GitHub account
Host github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa_account1
  IdentitiesOnly yes

# Account 2 - Second GitHub account
Host github-account2
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa_account2
  IdentitiesOnly yes

Here:

github.com is for account1 (default GitHub account).

github-account2 is a custom alias for account2. This ensures the right SSH key is used.

🧑‍💻 Step 3: Clone Repositories Using the Correct Account

When cloning a repository, make sure you use the correct alias for the second account.

# Clone with Account 1 (default):
git clone git@github.com:account1/repo-name.git

# Clone with Account 2:
git clone git@github-account2:account2/repo-name.git

Note: Use github-account2 as the host to ensure that account2’s SSH key (id_rsa_account2) is used.

📝 Step 4: Set Git Configuration for Each Repository (Optional)

To make sure you’re committing with the correct user for each project, set the user.name and user.email for each repo.

For Account 1:

git config user.name "account1"
git config user.email "your_email1@example.com"

For Account 2:

git config user.name "account2"
git config user.email "your_email2@example.com"

✅ Step 5: Test Which SSH Key Is in Use (Optional)

To check which SSH key is being used:

For Acount 1:

ssh -T git@github.com
# You should see:
# Hi account1! You've successfully authenticated...

For Acount 2:

ssh -T git@github-account2
# You should see:
# Hi account2! You've successfully authenticated...

This confirms the correct SSH key is in use.

🌟 Conclusion

You now have separate SSH keys configured for two GitHub accounts. By using different aliases in the SSH configuration, you can easily manage multiple GitHub accounts on the same machine. Always remember to use the correct SSH alias when cloning repositories and pushing changes!