Authentication Token Inspector

JWT Decoder & Token Security Inspector

Inspect JSON Web Tokens in real time. Validate standard claims (`sub`, `iss`, `aud`, `exp`), check cryptographic expiration timestamps, and detect unsigned or insecure algorithm settings.

JWT & Token Security Inspector

Client-Side

Decode, inspect claims, check expiration, and audit security vulnerabilities in JSON Web Tokens.

Encoded JWT String:249 chars

Algorithm:HS256

Type:JWT

Subject (sub):1234567890

Expires:1/15/2027, 8:00:00 AM

Header: Algorithm & Token Type

{
  "alg": "HS256",
  "typ": "JWT"
}

Payload: Decoded Claims & Data

{
  "sub": "1234567890",
  "name": "John Chanthy",
  "admin": true,
  "roles": [
    "admin",
    "security_auditor"
  ],
  "iat": 1700000000,
  "exp": 1800000000
}

100% Client-Side Decoded: Tokens never leave browser memorySecureStack Auth

Full Claim Parsing

Decodes Base64Url-encoded headers and payloads into formatted, syntax-highlighted JSON with 1-click export.

Algorithm Vulnerability Scan

Warns about `alg: none` exploits, missing expiration parameters, and sensitive credentials leaked in payloads.

Strict Zero Logging

Processed 100% locally in your browser. Tokens and secret authorization keys are never transmitted over the network.