Ed25519 & X25519 Key Generator
Modern Curve25519 signing and key-exchange keys.
Free · no sign-up · runs locally·
About this tool
Ed25519 (signatures) and X25519 (Diffie-Hellman key agreement) are built on Curve25519 — fast, constant-time by design, and free of the parameter choices that made older curves error-prone. They are the modern default for SSH keys, software signing, and TLS key exchange.
Keys are generated locally with the Web Crypto API and exported as PKCS#8 / SPKI PEM. Requires a recent browser; Safari 17+, Chrome 113+, and Firefox 119+ all support Ed25519 natively.
Like everything on encrypt.tools, this runs entirely in your browser — nothing you enter is transmitted or stored.
Do the same in a terminal
Reproduce or cross-check this tool with standard command-line utilities. For deterministic operations like hashing and encoding, the output matches exactly.
openssl genpkey -algorithm ED25519 -out ed25519.pem
openssl genpkey -algorithm X25519 -out x25519.pem
openssl pkey -in ed25519.pem -puboutFrequently asked questions about Ed25519 / X25519 Keys
What's the difference between Ed25519 and X25519?+
Ed25519 is for digital signatures; X25519 is for Diffie-Hellman key agreement. Both are built on Curve25519 and are the modern defaults for SSH, signing, and key exchange.
Why is Ed25519 recommended?+
It's fast, constant-time by design (resisting timing attacks), and free of the risky parameter choices older curves had. It's the default for new SSH keys and software signing.
Does my browser support it?+
Recent versions do — Chrome 113+, Safari 17+, and Firefox 119+ all support Ed25519 in the Web Crypto API. If generation fails, update your browser.
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