X25519
Compute an X25519 shared secret from 32-byte private & public keys (hex). Paste your data, then click to dissect it. Everything runs on your device, nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
(keys in More settings)
Example Output
Shared secret (hex): 9d2e…
How to Use
- 1Paste your data (PEM/Base64/token) into the Input field.
- 2Click the button (or press Ctrl+Enter) to dissect it.
- 3Read the decoded result in the Output field.
About X25519
X25519 is a Diffie-Hellman key exchange function based on Curve25519. It is fast, secure, and designed to resist implementation mistakes — the modern de facto standard (TLS 1.3, Signal, WireGuard, SSH).
This tool computes the shared secret from your private key (32 bytes, hex) and a peer public key (32 bytes, hex). As with ECDH, both parties get an identical secret.
Always derive the final key from this shared secret using HKDF before using it for encryption. X25519 is a more modern, recommended variant than NIST-curve ECDH.
FAQ
Are my data or keys sent to a server?
No. X25519 runs entirely in your browser using the Web Crypto API and client-side libraries. Your data, passwords, and keys never leave your device.