JWT Decoder

Decode and verify JSON Web Tokens. View header, payload, and signature. All processing done locally.

Features

  • 🔓 Decode JWT tokens instantly
  • 📋 View header, payload, and signature
  • ⏰ Show token expiration time
  • 📋 Copy decoded sections
  • ✨ Syntax highlighting
  • 🔒 All processing done locally (no server)
  • 🌙 Dark mode support
  • 📱 Fully responsive design

How to Use

  1. Paste JWT - Enter your JWT token in the input area
  2. Decode - Click "Decode JWT" button
  3. View - See decoded header, payload, and signature
  4. Copy - Click copy buttons to copy individual sections

About JWT (JSON Web Tokens)

JWT is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. JWTs are commonly used for authentication and authorization.

JWT Structure

A JWT consists of three parts separated by dots (.):

  • Header: Contains token type and signing algorithm
  • Payload: Contains claims (user data, expiration, etc.)
  • Signature: Verifies token hasn't been tampered with

Common Claims

  • iss: Issuer of the token
  • sub: Subject (user ID)
  • aud: Audience
  • exp: Expiration time
  • iat: Issued at time
  • nbf: Not before time

Security Note

⚠️ This tool only decodes JWTs. It does NOT verify signatures. Never paste sensitive tokens from production systems into online tools. Use this for development and debugging only.

✓ Success!