JWK Viewer & Generator

Inspect JSON Web Keys (JWK) and key sets (JWKS): view algorithm, use, and curve details, compute RFC 7638 thumbprints, or generate brand-new RSA, EC, or symmetric keys — entirely in your browser via the Web Crypto API.

Input JWK / JWKS
Drop JSON file here
Key Details

Features

🗝️ Inspect Any Key

  • Single JWK or a full JWKS key set
  • RSA, EC, and symmetric (oct) keys
  • Flags private key material automatically
  • RFC 7638 SHA-256 thumbprint for every key

🎲 Generate New Keys

  • RSA-2048 key pairs for RS256
  • EC P-256 key pairs for ES256
  • Symmetric HS256 keys for HMAC signing
  • Uses the browser's native Web Crypto API

⚡ Privacy-First

  • Keys are generated and analyzed locally
  • Nothing is ever uploaded to a server
  • Pairs well with our JWT Decoder
  • Useful for debugging OAuth/OIDC jwks_uri endpoints

JWK & JWKS Guide

A JSON Web Key (JWK, RFC 7517) is a JSON representation of a cryptographic key used to sign or verify JWTs and JWEs. A JWKS (JSON Web Key Set) bundles multiple JWKs under a "keys" array — this is exactly what identity providers expose at their jwks_uri endpoint for verifying tokens. This tool decodes either shape, surfaces the fields you need for debugging, and computes each key's canonical thumbprint per RFC 7638 so you can confirm which key a token was signed with (matching its kid).

Frequently Asked Questions

What is a JWK thumbprint used for?

RFC 7638 defines a canonical way to hash a key's required members into a short, unique identifier. It's commonly used as a stable kid value or to confirm two JWK representations refer to the same underlying key.

Is it safe to paste a private key here?

All parsing and key generation happens locally in your browser using the Web Crypto API — nothing is sent to a server. That said, treat any real private key material as sensitive and avoid pasting production secrets into any web tool, including this one.

Which key types are supported?

Viewing supports RSA, EC, OKP, and oct (symmetric) keys. Generation currently produces RSA-2048 (RS256), EC P-256 (ES256), and symmetric HS256 keys — the most common algorithms used by JWT libraries.