If you’re still cloning repos with HTTPS and typing your password — or using a personal access token — this guide is for you.
SSH keys are faster, more secure, and once set up, completely invisible. You just run git push and it works.
Step 1: Generate an SSH Key
The command is the same on all platforms (macOS, Linux, WSL on Windows):
ssh-keygen -t ed25519 -C "[email protected]"Use the same email you use for GitHub. When prompted:
- File location: Press Enter to accept the default (
~/.ssh/id_ed25519) - Passphrase: Enter a passphrase (recommended) or press Enter for none
This creates two files:
~/.ssh/id_ed25519— your private key (never share this)~/.ssh/id_ed25519.pub— your public key (what you give to GitHub)
Note: If you’re on a very old system that doesn’t support Ed25519, use RSA instead:
ssh-keygen -t rsa -b 4096 -C "[email protected]"
Step 2: Add the Key to ssh-agent
The ssh-agent holds your key in memory so you don’t have to type your passphrase every time.
macOS
eval "$(ssh-agent -s)"
ssh-add --apple-use-keychain ~/.ssh/id_ed25519The --apple-use-keychain flag saves the passphrase to macOS Keychain automatically.
Also add this to ~/.ssh/config (create the file if it doesn’t exist):
Host github.com
AddKeysToAgent yes
UseKeychain yes
IdentityFile ~/.ssh/id_ed25519Ubuntu / Linux
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519To make this persist across sessions, add to your ~/.bashrc or ~/.zshrc:
# Start ssh-agent if not running
if [ -z "$SSH_AUTH_SOCK" ]; then
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
fiWindows (native — Git Bash or PowerShell)
# Enable and start the ssh-agent service
Get-Service -Name ssh-agent | Set-Service -StartupType Automatic
Start-Service ssh-agent
# Add your key
ssh-add $env:USERPROFILE\.ssh\id_ed25519Windows (WSL — Ubuntu inside Windows)
WSL behaves like Ubuntu. Use the Linux instructions above.
Step 3: Copy Your Public Key
You need to give GitHub your public key (the .pub file):
macOS
pbcopy < ~/.ssh/id_ed25519.pubUbuntu / Linux
# Install xclip if not available
sudo apt install xclip
xclip -selection clipboard < ~/.ssh/id_ed25519.pub
# or just print and copy manually:
cat ~/.ssh/id_ed25519.pubWindows (Git Bash)
clip < ~/.ssh/id_ed25519.pubWindows (PowerShell)
Get-Content $env:USERPROFILE\.ssh\id_ed25519.pub | Set-ClipboardStep 4: Add the Key to GitHub
- Go to github.com and log in
- Click your avatar → Settings
- In the left sidebar: SSH and GPG keys
- Click New SSH key
- Give it a title (e.g., “MacBook Pro” or “Work Ubuntu”)
- Paste your public key
- Click Add SSH key
Step 5: Test the Connection
ssh -T [email protected]You should see:
Hi username! You've successfully authenticated, but GitHub does not provide shell access.If it says Permission denied, see the troubleshooting section below.
Step 6: Clone with SSH (not HTTPS)
Now use SSH URLs when cloning:
# SSH (use this now)
git clone [email protected]:username/repo.git
# HTTPS (old way — requires password/token)
git clone https://github.com/username/repo.gitFor repos you already cloned with HTTPS, switch them:
cd myrepo
git remote set-url origin [email protected]:username/repo.git
# Verify
git remote -v
# origin [email protected]:username/repo.git (fetch)
# origin [email protected]:username/repo.git (push)Multiple GitHub Accounts (Work + Personal)
If you use two GitHub accounts on the same machine, you need separate keys and an SSH config to route them correctly.
Generate a second key
ssh-keygen -t ed25519 -C "[email protected]" -f ~/.ssh/id_ed25519_workAdd the work key to your work GitHub account (same Step 3–4 as above).
Configure ~/.ssh/config
# Personal GitHub
Host github.com
HostName github.com
User git
IdentityFile ~/.ssh/id_ed25519
# Work GitHub
Host github-work
HostName github.com
User git
IdentityFile ~/.ssh/id_ed25519_workUse the alias when cloning work repos
# Instead of: git clone [email protected]:company/repo.git
git clone git@github-work:company/repo.gitGit sees github-work and uses your work key. GitHub sees your work account. It routes correctly.
Troubleshooting
”Permission denied (publickey)”
# Debug the connection
ssh -vT [email protected]Look for:
- “Offering public key” — which key is being tried
- “Server accepts key” — connection succeeded
- “Permission denied” — key not on GitHub, or wrong key being offered
Common fixes:
# Make sure the key is loaded
ssh-add -l
# If not listed, add it
ssh-add ~/.ssh/id_ed25519
# Make sure permissions are correct
chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_ed25519
chmod 644 ~/.ssh/id_ed25519.pub
chmod 644 ~/.ssh/config“Too many authentication failures”
Your agent is trying too many keys. Add this to ~/.ssh/config:
Host github.com
IdentitiesOnly yes
IdentityFile ~/.ssh/id_ed25519“ssh-add: Could not open a connection to your authentication agent”
The agent isn’t running:
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519On Windows — “WARNING: UNPROTECTED PRIVATE KEY FILE!”
# Fix permissions in PowerShell
icacls $env:USERPROFILE\.ssh\id_ed25519 /inheritance:r
icacls $env:USERPROFILE\.ssh\id_ed25519 /grant:r "$env:USERNAME:R"Summary
# The whole setup in one place:
ssh-keygen -t ed25519 -C "[email protected]"
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
cat ~/.ssh/id_ed25519.pub # copy this → GitHub Settings → SSH Keys
ssh -T [email protected] # test itOnce SSH is set up, you’ll never touch a personal access token again.
Don’t have Git installed yet? Start here: How to Install Git on Ubuntu, macOS and Windows.
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