JWK to PEM Converter

Convert RSA and EC JSON Web Keys into standard PEM files entirely in your browser. No uploads, no server processing.

Input JWK

Paste a JWK object or JWKS with a keys array

PEM Output

SPKI for public keys, PKCS8 for private keys

Private by design

Conversion uses the browser Web Crypto API locally. Keys are not uploaded or sent to a backend.

RSA and EC support

Supports RSA keys with n/e/d fields and EC keys for common curves such as P-256, P-384, and P-521.

Standard PEM output

Public keys export as SPKI PEM and private keys export as PKCS8 PEM for compatibility with OpenSSL and OAuth tooling.

How to use this JWK to PEM converter

  1. Paste a single JWK object or a JWKS object containing a keys array.
  2. Click Convert to PEM. If a JWKS is provided, the first key is converted.
  3. Copy or download the PEM file for use with OpenSSL, JWT libraries, OAuth providers, or API clients.