How to Set Up Multiple SSH Keys for GitHub Accounts on macOS: A Step-by-Step Guide

Managing multiple GitHub accounts (e.g., work, personal, or client projects) on a single macOS machine can lead to SSH key conflicts. Using separate SSH keys for each account ensures seamless authentication and better organization. In this guide, you’ll learn how to set up and manage multiple SSH keys for GitHub on macOS.

Why Use Multiple SSH Keys for GitHub?

• Avoid Conflicts: Prevent authentication errors when switching between accounts.
• Enhanced Security: Isolate work and personal projects.
• Organization: Easily manage contributions to different repositories.

Prerequisites

• macOS installed (any modern version).
• Basic familiarity with Terminal and GitHub.
• Two or more GitHub accounts.

Step 1: Generate SSH Keys for Each GitHub Account

1. Open Terminal and navigate to your SSH directory:

cd ~/.ssh

2. Create a new SSH key for your first account (e.g., work

ssh-keygen -t ed25519 -C "[email protected]"

• When prompted, name the key: id_ed25519_work.
• Add a passphrase for security (optional).

3. Repeat for your second account (e.g., personal):

ssh-keygen -t ed25519 -C "[email protected]"

Name this key: id_ed25519_personal.

Step 2: Add SSH Keys to the SSH Agent

The SSH agent manages your keys in the background.

1. Start the SSH agent:

eval "$(ssh-agent -s)"

2. Add your keys to the agent and macOS Keychain (saves passphrases):

ssh-add --apple-use-keychain ~/.ssh/id_ed25519_work
ssh-add --apple-use-keychain ~/.ssh/id_ed25519_personal

Step 3: Configure the SSH Config File

Create/update ~/.ssh/config to route traffic to the correct keys.

1. Open the config file in a text editor:

nano ~/.ssh/config

2. Add the following entries (adjust HostName, User, and IdentityFile):

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

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

3. Save and exit (Ctrl + X, then Y).