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JWT Decoder & Validator

Decode and validate JSON Web Tokens (JWT) with detailed header and payload inspection.

JWT Token Input

Syntax: jwt

Decoded JWT

Output will appear here

Format: json

How It Works

Privacy First

This jwt decoder & validator processes your data entirely in your browser. No data is uploaded to any server, ensuring complete privacy and security.

Lightning Fast

Instant processing with real-time validation and error detection. No waiting, no delays - just immediate results.

Versatile Use Cases

  • Debug authentication issues in web applications
  • Inspect JWT token structure and claims
  • Validate token expiration and issued dates

Mobile Friendly

Responsive design that works perfectly on all devices and screen sizes. Touch-friendly interface for mobile users.

Frequently Asked Questions

What is a JWT?
JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. It consists of three Base64-encoded parts: header, payload, and signature.
Can this tool verify JWT signatures?
This tool can decode and inspect JWT structure but cannot verify signatures since that requires the secret key or public key used for signing, which should never be shared.
What are the three parts of a JWT?
Header (contains algorithm and token type), Payload (contains claims/data), and Signature (verifies the token hasn't been tampered with).
What are JWT claims?
Claims are statements about an entity (typically the user) and additional data. Standard claims include iss (issuer), sub (subject), aud (audience), exp (expiration), and iat (issued at).
Is it safe to decode JWTs online?
For production tokens with sensitive data, use local tools. This decoder works client-side only, but avoid pasting real tokens with personal or sensitive information.

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