JWT Decoder

Securely analyze JSON Web Tokens

100% Client-side
🔐

Security Notice

This tool processes JWTs exclusively in your browser. Unlike jwt.io, no tokens are transmitted to servers. Ideal for production tokens with sensitive data.

â„šī¸ What is a JWT?

A JSON Web Token (JWT) is a compact, URL-safe format for transferring claims between two parties. It consists of three Base64-encoded parts: Header, Payload, and Signature.

Header

Contains the algorithm and token type

Payload

Contains the claims/data of the token

Signature

Verifies the integrity of the token

How to Decode a JWT Token

  1. Paste your JWT token into the input field
  2. The decoder automatically parses the three parts (header, payload, signature)
  3. View the decoded header with algorithm information
  4. Examine the payload claims with explanations
  5. Check token validity and expiration status

Frequently Asked Questions

Is it safe to paste my JWT here?

Yes, unlike jwt.io, this tool processes tokens entirely in your browser. No data is ever sent to any server. Safe for production tokens with sensitive data.

What is a JWT?

JWT (JSON Web Token) is a compact, URL-safe way to represent claims between parties. It consists of three Base64-encoded parts: Header, Payload, and Signature.

Can this tool verify signatures?

This tool decodes and displays tokens but cannot verify signatures without the secret key (symmetric) or public key (asymmetric). Signature verification requires the key.

What do the standard claims mean?

Common claims: iss (issuer), sub (subject), aud (audience), exp (expiration), iat (issued at), nbf (not before), jti (JWT ID). Each has a specific purpose in token validation.

Why is my token showing as expired?

The 'exp' claim contains a Unix timestamp. If the current time exceeds this value, the token is expired. Tokens are designed to have limited lifetimes for security.

Follow Me