# How to Set Up GitHub SSH Authentication - Complete Setup Guide for Windows, Linux, and macOS If you're still entering credentials every time you push or pull code from GitHub, it's time to switch to SSH authentication. SSH (Secure Shell) allows GitHub to verify your identity using cryptographic keys instead of passwords or personal access tokens. Once configured, Git operations become faster, more secure, and significantly more convenient. In this guide, you'll learn how to set up GitHub SSH authentication using ED25519 keys on Windows, Linux, and macOS. ## Why Use SSH with GitHub? SSH authentication offers several benefits: * Secure cryptographic authentication * No need to repeatedly enter credentials * Faster Git operations * Better support for automation and CI/CD workflows * Recommended by GitHub for repository access Once configured, you can clone, pull, and push repositories without being prompted for GitHub credentials. ## Prerequisites Before getting started, make sure Git is installed on your system. > **Tip:** If Git is not installed, use the appropriate installation method for your operating system. ### Windows Download and install Git from: ```text https://git-scm.com/downloads ``` ### Ubuntu / Debian ```bash sudo apt update sudo apt install git ``` ### Fedora ```bash sudo dnf install git ``` ### Arch Linux ```bash sudo pacman -S git ``` ### macOS (Homebrew) ```bash brew install git ``` Verify the installation: ```bash git --version ``` You should see the installed Git version displayed in your terminal. * * * ## Step 1: Generate an SSH Key Open your terminal and run: ```bash ssh-keygen -t ed25519 -C "your-email@example.com" ``` Replace the email address with the one associated with your GitHub account. Example: ```bash ssh-keygen -t ed25519 -C "john@example.com" ``` You'll be prompted to choose a location for the key: ```text Enter file in which to save the key ``` Simply press Enter to use the default location. You will then be asked to create a passphrase: ```text Enter passphrase (empty for no passphrase): ``` A passphrase is optional but recommended because it adds an extra layer of protection if your private key is ever exposed. After completion, you should see output similar to: ```text Your identification has been saved in ~/.ssh/id_ed25519 Your public key has been saved in ~/.ssh/id_ed25519.pub ``` * * * ## Step 2: Verify the SSH Key Files Verify that the key pair was created successfully. ### Linux / macOS ```bash ls -la ~/.ssh ``` ### Windows ```cmd dir %USERPROFILE%\.ssh ``` You should see files similar to: ```text id_ed25519 id_ed25519.pub ``` The private key: ```text id_ed25519 ``` The public key: ```text id_ed25519.pub ``` > Never share your private key with anyone. Only the public key should be uploaded to GitHub. * * * ## Step 3: Display Your Public Key Copy your public key using one of the following commands. ### Linux / macOS ```bash cat ~/.ssh/id_ed25519.pub ``` ### Windows ```cmd type %USERPROFILE%\.ssh\id_ed25519.pub ``` The output will look similar to: ```text ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAI... your-email@example.com ``` Copy the entire line. * * * ## Step 4: Add the SSH Key to GitHub Log in to your GitHub account and navigate to: ```text https://github.com/settings/keys ``` Click **New SSH Key**. Fill out the form: **Title** ```text My Laptop ``` **Key Type** ```text Authentication Key ``` Paste the public key into the key field and click **Add SSH Key**. GitHub may ask you to confirm your password or complete two-factor authentication. Once saved, your device is authorized to authenticate with GitHub using SSH. * * * ## Step 5: Test the SSH Connection Now it's time to verify that everything is working correctly. Run: ```bash ssh -T git@github.com ``` The first time you connect, you'll likely see: ```text The authenticity of host 'github.com' can't be established. Are you sure you want to continue connecting (yes/no/[fingerprint])? ``` Type: ```text yes ``` and press Enter. If the setup is successful, GitHub will respond with: ```text Hi yourusername! You've successfully authenticated, but GitHub does not provide shell access. ``` This confirms that your SSH key is correctly configured and recognized by GitHub. * * * ## Step 6: Configure Git Identity Before working with repositories, configure your Git username and email. ```bash git config --global user.name "Your Name" git config --global user.email "your-email@example.com" ``` Verify the configuration: ```bash git config --global --list ``` You should see your configured username and email address in the output. * * * ## Step 7: Clone a Repository Using SSH Instead of cloning repositories using HTTPS: ```text https://github.com/username/repository.git ``` Use the SSH URL: ```text git@github.com:username/repository.git ``` Example: ```bash git clone git@github.com:username/repository.git ``` The repository will now use SSH authentication automatically. * * * ## Step 8: Convert Existing Repositories from HTTPS to SSH If you already have repositories cloned using HTTPS, you can switch them to SSH without recloning. Check the current remote: ```bash git remote -v ``` Example HTTPS remote: ```text https://github.com/username/repository.git ``` Change it to SSH: ```bash git remote set-url origin git@github.com:username/repository.git ``` Verify the update: ```bash git remote -v ``` You should now see: ```text git@github.com:username/repository.git ``` * * * ## Step 9: Test Git Operations Try pulling changes: ```bash git pull ``` Or pushing changes: ```bash git push ``` If everything is configured correctly, Git will authenticate automatically without requesting your GitHub credentials. * * * ## Common Issues and Fixes ### Permission Denied (publickey) If you receive: ```text Permission denied (publickey). ``` Check the following: * The public key was added to the correct GitHub account * The key was copied completely * The private key exists in your `.ssh` directory * You're using the correct GitHub account Verify authentication again: ```bash ssh -T git@github.com ``` * * * ### Repository Not Found Ensure: * The repository exists * You have access permissions * The remote URL is correct Check your remote URL: ```bash git remote -v ``` * * * ### Wrong GitHub Account If you use multiple GitHub accounts, create separate SSH keys and configure SSH host aliases using the SSH config file. This allows each repository to authenticate using the appropriate account. * * * ### Verify Which Remote Is Being Used Run: ```bash git remote -v ``` Expected output: ```text origin git@github.com:username/repository.git (fetch) origin git@github.com:username/repository.git (push) ``` If you still see HTTPS URLs, update them using the commands shown earlier. * * * ## Understanding ED25519 You may have noticed the command uses: ```bash ssh-keygen -t ed25519 ``` ED25519 is a modern public-key signature algorithm designed to provide strong security with smaller key sizes and better performance than older alternatives like RSA. GitHub recommends ED25519 keys whenever possible. Unless you have a specific compatibility requirement, ED25519 is the preferred choice. * * * ## Final Thoughts SSH authentication is one of the first configurations every developer should set up after installing Git. The process takes only a few minutes, but it provides long-term benefits: * Improved security * Faster authentication * Better automation support * Cleaner Git workflows Once configured, you'll be able to interact with GitHub repositories securely and efficiently without constantly entering credentials. Whether you're contributing to open source projects, managing personal repositories, or working in professional development environments, SSH authentication is a setup worth implementing from day one.