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JWT Decoder

Decode and inspect JWT tokens — header, payload, signature, expiration.

Free online JWT decoder and inspector. Decode and inspect JSON Web Tokens — header, payload, signature, and expiration. All processing is client-side for maximum security.

Features

  • Decode JWT header, payload, and signature
  • Check token expiration with countdown timer
  • View token claims in formatted JSON
  • Optional signature verification
  • Support for all standard algorithms
  • Copy decoded output as JSON

Use Cases

  • Debugging authentication tokens during development
  • Inspecting JWT claims for access control debugging
  • Validating token expiration and issuance dates
  • Verifying JWT format compliance

Tags

jwt decoderjwt debuggerjwt inspectordecode jwt token

Frequently Asked Questions

Is my JWT token safe?
Yes, all decoding happens in your browser. Your token is never sent to any server.
What signature algorithms are supported?
All standard algorithms: HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, ES512, EdDSA.
Can I verify the signature?
Signature verification requires the secret key. The tool can decode any token; verification works if you provide the key.