Configuring Two GitHub Access Keys on One Machine

Configuring Two GitHub Access Keys on One Machine

This guide shows how to configure two GitHub accounts on the same machine using two SSH keys and an SSH config file:

  • one for your personal account
  • one for your organization/work account

This is the most reliable setup when the two accounts access different repositories.

Overview

The recommended approach is:

  1. Generate one SSH key per GitHub account
  2. Add both keys to ssh-agent
  3. Configure ~/.ssh/config with two host aliases
  4. Use the correct alias in each repository’s remote URL
  5. Optionally set different Git commit identities per repository

1. Generate Two SSH Keys

Create one key for your personal GitHub account and one for your organization account.

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ssh-keygen -t ed25519 -C "your_personal_email@example.com"
# Save as: ~/.ssh/id_ed25519_github_personal

ssh-keygen -t ed25519 -C "your_work_email@example.com"
# Save as: ~/.ssh/id_ed25519_github_work

After that, upload the public keys to the correct GitHub accounts:

  • ~/.ssh/id_ed25519_github_personal.pub -> personal GitHub account
  • ~/.ssh/id_ed25519_github_work.pub -> organization/work GitHub account

2. Add Both Keys to ssh-agent

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eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519_github_personal
ssh-add ~/.ssh/id_ed25519_github_work

This allows SSH to manage both keys more conveniently.

3. Configure ~/.ssh/config

Edit your SSH config file:

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Host github-personal
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_ed25519_github_personal
  IdentitiesOnly yes

Host github-work
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_ed25519_github_work
  IdentitiesOnly yes

Why this works

  • github-personal and github-work are local SSH aliases
  • both point to github.com
  • each alias forces SSH to use a specific private key
  • IdentitiesOnly yes prevents SSH from using the wrong key from ssh-agent

4. Test Each Account

Run:

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ssh -T git@github-personal
ssh -T git@github-work

If everything is configured correctly, GitHub should confirm authentication for each account.

5. Clone Repositories with the Correct Alias

Personal repository

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git clone git@github-personal:yourname/my-repo.git

Organization repository

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git clone git@github-work:your-org/team-repo.git

Important: do not use git@github.com:... if you want SSH to choose between accounts automatically.
Use the host aliases defined in ~/.ssh/config.

6. Update Existing Repository Remotes

If you already cloned a repository, change its remote URL.

Personal repository

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

Organization repository

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git remote set-url origin git@github-work:your-org/team-repo.git

7. Optional: Set Different Git Commit Identities

SSH authentication and Git commit identity are different things.

If you also want commits to show different names or emails, configure them per repository.

In a personal repository

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git config user.name "Your Personal Name"
git config user.email "your_personal_email@example.com"

In a work repository

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git config user.name "Your Work Name"
git config user.email "your_work_email@example.com"

8. Troubleshooting

If Git still uses the wrong account, run SSH in verbose mode:

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ssh -vT git@github-work

Check the output to confirm which IdentityFile is being used.

For long-term maintenance, use:

  • one SSH key per GitHub account
  • SSH host aliases in ~/.ssh/config
  • repository-specific remote URLs
  • repository-specific Git user.name and user.email if needed

This setup is simple, stable, and works well when personal and organization accounts access different repositories.