JWK ↔ PEM Converter
Convert JSON Web Keys to PEM and PEM keys back to JWK.
About the JWK ↔ PEM Converter
Convert public and private keys between JWK (JSON Web Key) and PEM (SPKI / PKCS#8) using the browser's Web Crypto API. Supports RSA keys for RSASSA-PKCS1-v1_5, RSA-PSS and RSA-OAEP, and elliptic-curve keys on P-256, P-384 and P-521. The key never leaves your device.
Examples
EC public key
JSON{ "kty": "EC", "crv": "P-256", "x": "...", "y": "..." }Output
-----BEGIN PUBLIC KEY-----Keyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- OpenSSL commands and key formats, explained without the man page
CSRs, self-signed certificates, PEM vs DER vs PKCS#8 vs JWK, and how to check what a certificate actually contains.
Version 1.0.0 · Updated 2026-08-22 · Runs entirely in your browser