Is this a real SSH key fingerprint?

No. The fingerprint is random bytes formatted exactly like a real SSH fingerprint. It corresponds to no actual key, so it is safe placeholder data for testing UIs and configuration, never for granting access.

What is the difference between the MD5 and SHA256 formats?

Older OpenSSH versions displayed an MD5 fingerprint as 16 colon-separated hex bytes, often prefixed with MD5:. Modern OpenSSH shows a SHA256 fingerprint as unpadded base64 prefixed with SHA256:. The format is a display choice over the same hashing idea.

Why does the SHA256 form drop the padding?

OpenSSH renders the 32-byte SHA-256 digest as base64 and strips the trailing equals padding, which is why a SHA256 fingerprint ends abruptly. This tool reproduces that exact convention so the string matches real output.

What does the key type label mean?

SSH keys come in types such as RSA, ECDSA, and ED25519. Tools often show the type and bit size alongside the fingerprint. The label here is cosmetic context and does not change the random bytes that make up the fingerprint.

Are the bytes random?

Yes. The tool uses the browser Web Crypto random generator, so each fingerprint is unpredictable. It is still a placeholder, not the hash of any real public key, and must never be added to an authorized_keys or known_hosts trust list.

What is the Fake SSH Key Fingerprint Generator?

Generate SSH key fingerprint strings in the legacy MD5 colon-hex format and the modern SHA256 base64 format for testing SSH key management UIs and deployment configuration. Random placeholders, not real keys. It runs free in your browser on Gera Tools, with nothing uploaded.

Fake SSH Key Fingerprint Generator

Name: Fake SSH Key Fingerprint Generator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Generate SSH key fingerprints in both the legacy MD5 colon-hex form and the modern SHA256 base64 form, from cryptographically random bytes. Ideal for populating SSH key management screens and deployment config with realistic placeholders.

When you need fake fingerprints

SSH key fingerprints appear in a number of places in real infrastructure tooling, and building or testing that tooling requires realistic-looking placeholder data:

SSH key management UI testing — screens that list registered SSH keys for users typically show the fingerprint alongside the key name and date added. Seeding a test database with realistic fingerprints lets you verify layout, truncation, copy buttons, and sorting without ever generating or exposing real keys.
CI/CD and deployment config — pipeline configs, known_hosts entries in test environments, and host verification stubs often require a fingerprint in the correct format. A fake one in the right format lets the pipeline reach the SSH parsing logic without requiring a live server.
Documentation and screenshots — help docs, onboarding flows, and product screenshots showing SSH key setup screens need realistic fingerprints. Using SHA256:aaaabbbbcccc... looks obviously fake; a properly formatted random fingerprint reads authentically.
Developer tooling and fixture files — unit or integration tests for anything that parses, displays, or stores SSH fingerprints need correctly-formatted test inputs.

How it works

OpenSSH fingerprints a public key by hashing its blob and displaying the digest. Two display conventions exist:

MD5     16 bytes -> "MD5:" + colon-separated lowercase hex
SHA256  32 bytes -> "SHA256:" + unpadded base64

The tool draws the right number of random bytes from Web Crypto and renders them in the chosen convention, including the modern habit of stripping the base64 = padding. The bytes are random, not a hash of any real key, so the result is a safe stand-in.

Real SSH fingerprint format reference

For orientation, a real ssh-keygen -l output looks like this:

# Legacy MD5 (old OpenSSH):
2048 MD5:3d:a7:f8:6c:2b:0a:4e:7f:92:c1:ab:88:d3:02:ef:1c user@host (RSA)

# Modern SHA256 (current OpenSSH default):
256 SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8 user@host (ED25519)

The generated fingerprint matches the MD5:... or SHA256:... portion exactly. The bit-count prefix (2048 or 256) and the comment (user@host) are context you would add separately in your tooling.

Tips and notes

Match the format to your OpenSSH era: very old clients showed MD5 by default, while current ones default to SHA256. ED25519 keys are 256 bits and always use SHA256 in modern OpenSSH; RSA keys can be 2048 or 4096 bits but still display a SHA256 fingerprint of the same length. The optional key-type label (RSA, ECDSA, ED25519) is cosmetic — never add a generated fingerprint to known_hosts or authorized_keys, since it authenticates nothing and adding it to a trust list would cause a connection failure.