Why doesn't this tool just generate the key pair directly, like the RSA/ECDSA Key Generator does?

SSH key pairs are almost always generated locally with OpenSSH's own ssh-keygen, which also handles setting correct file permissions and (optionally) a passphrase-protected private key on disk, something a browser tool can't do for you. This tool focuses on getting the exact command right, rather than trying to reproduce ssh-keygen's file-handling behavior in the browser.

Should I choose Ed25519 or RSA?

Ed25519 is the modern default: shorter keys, faster operations, and supported by essentially all current SSH servers and services (GitHub, GitLab, most cloud providers). Choose RSA only if you know a specific older system you connect to doesn't support Ed25519 yet.

What does the -C comment actually do?

It's a label embedded in the public key file, purely informational, with no effect on the key's cryptographic behavior. It's commonly set to an email address or a short description (like "laptop-2026") so that when you see this key listed among others (in an authorized_keys file or a service's settings page), you know what it's for.

Is it safe to run ssh-copy-id with a command generated here?

The command itself is standard and safe, it copies your public key (never the private key) to a remote server's ~/.ssh/authorized_keys. Just make sure you replace user@remote-host with the actual server you intend to grant access to before running it.

ssh-keygen Command Generator

Overview

Introduction

Generating an SSH key pair is a one-line command, but the exact flags for algorithm, bit size, comment, and output path are easy to mix up or forget, especially if you don't run ssh-keygen often.

This tool builds that exact command, plus the handful of follow-up commands (permissions, ssh-agent, copying the public key) most people need right after.

What Is SSH Key Generator Commands?

A command-line reference generator: choose Ed25519 (the modern default) or RSA with a bit-size toggle, enter a comment and output filename, and get back the exact `ssh-keygen` invocation.

It also includes the natural next steps as separate commands: setting correct file permissions, loading the key into ssh-agent, copying the public key to a remote server, and printing the public key to paste manually.

How SSH Key Generator Commands Works

Your algorithm choice maps directly to `ssh-keygen`'s `-t` flag (`ed25519` or `rsa`), with `-b <size>` added only for RSA since Ed25519 has a fixed key size.

The comment (if provided) becomes the `-C` flag's value, and the filename becomes the `-f` flag's value, which also determines the follow-up commands' file paths (`<filename>.pub` for the public key).

When To Use SSH Key Generator Commands

Use it when setting up SSH access to a new server or service and you want the exact command without checking `man ssh-keygen` or an old note to yourself.

It's also useful as a quick reference for the full workflow (generate, secure permissions, load into the agent, deploy the public key), not just the generation step alone.

Often used alongside SSH Config File Generator.

Features

Advantages

Produces the exact, correctly-flagged command for either algorithm, no guessing at flag names or order.
Includes the realistic follow-up commands (chmod, ssh-agent, ssh-copy-id, cat) most people need immediately after generating a key.
Never asks for or handles real key material, since it only outputs commands for you to run yourself, there's nothing sensitive to leak.

Limitations

Doesn't generate any actual key material, unlike the RSA/ECDSA Key Generator tool, you still need to run the command in a real terminal.
Doesn't add a `-N` passphrase flag; ssh-keygen will prompt you interactively for a passphrase (or none) when you run the command.

Examples

An Ed25519 key with a comment and default filename

Input

algorithm: Ed25519, comment: alice@laptop-2026, filename: ~/.ssh/id_ed25519

Output

# Generate a new Ed25519 key pair
ssh-keygen -t ed25519 -C "alice@laptop-2026" -f ~/.ssh/id_ed25519

Ed25519 needs no bit-size flag, so the command is just -t, -C, and -f with your chosen values.

Best Practices & Notes

Best Practices

Prefer Ed25519 for any new key unless a specific legacy system requires RSA.
Set a real passphrase when ssh-keygen prompts for one, an unencrypted private key on disk is a single point of failure if that machine is ever compromised.
Use a distinct comment and filename per device or purpose (e.g. work laptop vs. personal desktop) rather than reusing one key pair everywhere.

Developer Notes

This is a pure string-templating function: given { algorithm, rsaBitSize, comment, filename }, it conditionally includes the `-b` flag only for RSA and the `-C` flag only when a comment is provided, then appends the standard follow-up command sequence (chmod 600, ssh-agent + ssh-add, ssh-copy-id, cat) using the same filename consistently across all of them.

SSH Key Generator Commands Use Cases

Generating a fresh SSH key pair for a new machine or a new service integration
Reference for the full key setup workflow beyond just the generation command
Standardizing key generation commands across a team with consistent comment/filename conventions

Common Mistakes

Forgetting the -b bit-size flag when generating an RSA key, silently falling back to ssh-keygen's default size instead of the one intended.
Running ssh-copy-id with the placeholder user@remote-host left unedited, pointing the command at nothing real.

Tips

Use the SSH Config Generator tool right after, to reference this key's filename in a Host block's IdentityFile field.

SSH Key Generator Commands