Security & Web

JWT Decoder

Decode JSON Web Tokens to inspect Header, Payload claims, and expiration.

Processed locally. Your input stays in this browser.
Security Disclaimer

⚠️ Security Disclaimer: Decoding a JWT reveals its payload contents but DOES NOT verify its signature. Anyone can issue a forged JWT with arbitrary payload. Never trust unverified JWT claims for security decisions.

1 line177 chars177 B
Algorithm: HS256Type: JWT
TOKEN ACTIVE

JOSE Header

JSON Tree ExplorerMax Depth 15 • Virtual Windowing Active
{
alg:"HS256",
typ:"JWT"
}

Payload Claims

JSON Tree ExplorerMax Depth 15 • Virtual Windowing Active
{
sub:"1234567890",
name:"John Doe",
iat:1516239022,
exp:2000000000
}
Raw Signature Component:
SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

How It Works

  • 1.Paste a JSON Web Token (encoded as header.payload.signature) into the editor.
  • 2.The tool decodes Base64URL header and payload parts locally in your browser.
  • 3.Inspect claim fields (subject, issuer, issued at, expiration time).

Common Use Cases

  • Debugging OAuth2 / OpenID Connect access tokens and ID tokens.
  • Inspecting custom claim attributes during backend API development.

Frequently Asked Questions

Does decoding a JWT verify its signature?

NO. Decoding extracts the payload for inspection but DOES NOT verify the secret key or public key signature.

Is my JWT sent to a remote server?

Never. Decoding is done 100% locally in your browser.

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