SSH Key Fingerprint Checker
Paste an OpenSSH public key to inspect it: key type, bit length, SHA256 fingerprint (the same format OpenSSH prints) and the legacy MD5 fingerprint. Weak and legacy key types get a clear warning. Everything runs in your browser — your key never leaves the page.
Key details
- Key type
- Key length
- Comment
- SHA256 fingerprint
- MD5 fingerprint
- Raw blob size
How it works
- The key is split into its three parts: the key type name, the base64-encoded key blob, and the optional comment.
- The blob is decoded and parsed field by field, exactly like the OpenSSH binary format (each field is a 4-byte length followed by that many bytes).
- The SHA256 fingerprint is the base64 of the SHA256 hash of the raw blob, without padding, prefixed with
SHA256:— identical to whatssh-keygen -lprints. - The MD5 fingerprint is the hex digest of the blob with a colon between every byte pair, matching the legacy OpenSSH format.
- ssh-dss and ssh-rsa1 are legacy types and are flagged. RSA keys shorter than 2048 bits are flagged as weak.