V · Security & Encoding
V · Security & EncodingAV-S01

AV-S01

JWT Decoder

Decode a JSON Web Token, check its time claims and verify the signature with a secret or public key.

● Runs on your device; nothing is uploaded

How to use it

  1. Paste the token into Encoded token; a leading "Bearer " is stripped.
  2. Read the Header, Payload and claim table, and the expiry status badge.
  3. For HS algorithms, enter the Secret and tick base64 if it is encoded.
  4. For other algorithms, paste a public key as PEM or JWK instead.
  5. Press Verify to check the signature.
Features
  • Verifies HS, RS, PS and ES (256/384/512) and EdDSA signatures
  • Explains registered claims and shows exp, nbf and iat as dates
  • Flags expired and not-yet-valid tokens
  • Rejects alg "none" and encrypted JWE tokens with a clear message
  • Uses the Web Crypto API; the token is not sent anywhere

For AI agents: avtools_jwt_decoder

AV-S01 · JWT Decoder

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