About this tool
You need an SSH key pair to log in to a server, to push to GitHub or GitLab and for deployments. This generator creates one right in your browser – no terminal, no installation: Ed25519 (recommended), ECDSA with P-256, P-384 or P-521, or RSA with 2048 to 4096 bit. Both keys come in the same OpenSSH format that ssh-keygen writes and can be downloaded as id_ed25519 and id_ed25519.pub.
For every key the tool shows the SHA-256 fingerprint and the randomart picture as printed by ssh-keygen -lv. In the second part you can paste any public key – such as a line from authorized_keys – and read its type, size, comment and SHA-256 and MD5 fingerprints to compare it with what GitHub or a server login shows.
The keys are created with your browser’s Web Crypto API and are never stored or transmitted. Create strong passwords with the Password Generator; read TLS certificates with the SSL Certificate Decoder.
How it works
- Choose the key type – Ed25519 if in doubt – and optionally enter a comment, e.g. name@laptop.
- The key pair is generated immediately. “Generate new” gives you a fresh one.
- Download both files, put them in ~/.ssh and restrict the private key with chmod 600.
- Add the public key to ~/.ssh/authorized_keys on the server or to the SSH settings of GitHub/GitLab.
Frequently asked questions
Is it safe to generate an SSH key in the browser?
The keys are created with your browser’s Web Crypto API, which uses the same cryptographically secure randomness as the operating system. Nothing leaves the page; there is no server call. For keys with very high protection needs (such as production servers), ssh-keygen on your own machine remains the first choice because no browser tab is involved.
Which key type should I choose?
Ed25519: short keys, fast and secure, supported by OpenSSH since version 6.5 (2014), GitHub, GitLab and every current system. RSA only for very old systems, and then with at least 3072 bit. ECDSA only if a policy requires the NIST curves.
How do I protect the private key with a passphrase?
The tool creates the key without a passphrase. Set one afterwards in the terminal with ssh-keygen -p -f ~/.ssh/id_ed25519 – the key stays the same, only the file is encrypted.
What is the randomart picture?
A visual representation of the fingerprint shown by ssh-keygen. People recognise a familiar picture faster than a long string. The picture here is computed exactly like ssh-keygen -lv does, so you can compare them directly.
Does the key work with PuTTY on Windows?
Yes. Windows 10 and 11 ship OpenSSH and use the files directly (folder C:\Users\<name>\.ssh). For PuTTY, import the private key in PuTTYgen (“Conversions → Import key”) and save it as .ppk.