How to use the SSH Key Generator tool
- Choose Ed25519 (recommended) or RSA.
- Enter a comment, such as your email or device name.
- Click “Generate SSH key”.
- Download the private key to ~/.ssh and add the public key to your server or Git account.
Ed25519 or RSA?
Ed25519 is the modern default: short keys, fast, and secure. GitHub, GitLab, Bitbucket and every OpenSSH server from the last ten years support it. Choose RSA only for old systems or devices that do not accept Ed25519.
Using the keys
- Save the private key as ~/.ssh/id_ed25519 and run chmod 600 on it.
- Add the public key (.pub) to ~/.ssh/authorized_keys on the server, or paste it into GitHub under Settings, SSH and GPG keys.
- Protect the private key with a passphrase: ssh-keygen -p -f ~/.ssh/id_ed25519.
Security
Keys are created with your browser’s secure random generator; the Ed25519 math is done by the audited TweetNaCl library. The private key is never sent anywhere. Generating keys directly with ssh-keygen on your own machine remains the gold standard for production access.
Frequently asked questions
Is the private key compatible with OpenSSH?
Yes. Ed25519 keys use the standard OPENSSH PRIVATE KEY format; RSA keys use the PEM format that OpenSSH also reads.
Why is there no passphrase?
Adding one requires bcrypt key derivation that is slow in a browser. Add a passphrase right after saving with ssh-keygen -p.
What is the fingerprint?
The SHA256 fingerprint identifies the key. It matches what ssh-keygen -lf and GitHub show.
Does it work on Windows?
Yes. Windows 10 and 11 include OpenSSH. Save the key in C:\Users\you\.ssh\.