SSH Key Decoder - Parse Public Keys & Show Fingerprints

Decode SSH public keys to view key type, size, fingerprint, and comment. Parse authorized_keys format. Supports RSA, ECDSA, Ed25519. Browser-based decoder.

SSH Public Key

Paste your SSH public key (from ~/.ssh/id_rsa.pub or authorized_keys)

Key Format Examples

RSA: ssh-rsa AAAAB3NzaC1...
Ed25519: ssh-ed25519 AAAAC3N...
ECDSA: ecdsa-sha2-nistp256 AAAAE2V...
DSA: ssh-dss AAAAB3NzaC1...

Paste an SSH public key to decode

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Frequently Asked Questions

An SSH public key authenticates users to servers without passwords. It's the safe-to-share part of a key pair. The private key stays secret; the public key goes in ~/.ssh/authorized_keys on servers.

RSA (2048-4096 bit), DSA (deprecated, 1024 bit), ECDSA (256/384/521 bit curves), and Ed25519 (256 bit, modern). Ed25519 is recommended for new keys due to speed and security.

A fingerprint is a short hash (MD5 or SHA256) of the public key. It's easier to verify than the full key. Used to confirm you're connecting to the right server or using the right key.

MD5 is the traditional format (16:27:ac:...), shown by older OpenSSH versions. SHA256 is newer, more secure, and default in modern OpenSSH (SHA256:abc123...). Both identify the same key.

The comment (usually user@host) helps identify which key is which. It's not used for authentication, just a label. You can change it without affecting the key's cryptographic properties.

No, and you shouldn't paste private keys anywhere online. This tool only decodes public keys (starting with ssh-rsa, ssh-ed25519, etc.). Keep private keys secure and never share them.

authorized_keys stores one public key per line, optionally with restrictions (command, from, no-port-forwarding). Format: [options] keytype base64-key [comment].

RSA key security depends on size. 1024-bit is deprecated (insecure). 2048-bit is minimum. 4096-bit is recommended for high-security. Ed25519 offers better security with smaller keys.

ECDSA uses elliptic curves: P-256 (nistp256), P-384 (nistp384), P-521 (nistp521). Higher numbers = more security but slower. Ed25519 is preferred over ECDSA for modern systems.

Yes. GitHub, GitLab, Bitbucket all use standard SSH public keys. Paste your key from ~/.ssh/id_rsa.pub to verify the type, size, and fingerprint before adding to your account.

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