JWK/JWKS check

Parse JWK or JWKS locally in the browser, display the key type, algorithm, use, and kid, and calculate the thumbprint.

Local browser processing
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User Guide

How to use JWK/JWKS to inspect

JWK/JWKS content is parsed only in the current browser; private-key fields are masked by default, and no remote addresses are requested or input is saved.

  1. Enter JWK

    Paste a single JWK or a JWKS JSON containing a keys array.

  2. Inspect fields

    View public metadata such as kty, alg, use, kid, curves, or moduli, and calculate the thumbprint.

  3. Copy report

    Copy the check results; public JWK fields are displayed in full, and private key content is masked only when the input contains private key members.

Limitations and Notes

  • The tool only parses the structure and calculates the thumbprint; it does not verify signatures, validate the certificate chain, or determine whether the key is trusted.
  • Remote JWKS, network requests, and actual API calls will not be executed.
  • Before processing private keys, confirm that the device, clipboard, and page environment are trusted, and clear the input when finished.

FAQ

Does it verify JWT signatures?

No. The tool only checks JWK/JWKS metadata and the thumbprint.

Why is the private-key field masked?

This is a default anti-leak measure to prevent the private key from being fully exposed when displaying the result.

Can I enter a remote JWKS address?

No. The tool will not fetch remote URL; manually copy the content in a trusted environment.

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