JWK to PEM Converter

Convert between JWK and PEM public keys

Runs in your browserUtility07Network & Web

What is JWK to PEM Converter?

This JWK converter translates in both directions between a JSON Web Key from a JWKS and a PEM-encoded public key, built on the browser's Web Crypto import and export routines. RSA public keys are supported today, and the conversion runs entirely in your browser.

How to use JWK to PEM Converter

  1. 1Choose the conversion direction.
  2. 2Paste a PEM public key or a single JWK object, not the whole JWKS array.
  3. 3Click Convert and copy the result.

Frequently asked questions

Which part of a JWKS do I paste in?+

A JWKS has the shape { "keys": [ ... ] }. Pull out the one object in that array whose kid matches your token and paste that object in full. Pasting the entire JWKS fails to import because of the extra wrapper layer.

Why are only public keys supported?+

Private keys have no business being pasted into a web page. Verifying a signature needs only the public key, and signing belongs on your backend. If you genuinely need to convert a private key, do it in a controlled environment with openssl or your language's SDK.

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