Back to projects

jwt-decoder

Smol educational app, exploring the basics of JWT Tokens & Opaque Tokens

TypeScript 1 0 Updated Apr 10, 2025
jwtjwt-authenticationjwt-tokenjwt-tokens

Token Explorer: JWT & Opaque Token Educational Tool

A comprehensive educational tool for understanding, creating, and decoding different types of authentication tokens. This project helps developers learn about JSON Web Tokens (JWTs) and Opaque Tokens through hands-on experimentation.

t0ken.vercel.app

🚀 Features

  • JWT Creation: Build and sign custom JWTs with your own header and payload
  • JWT Decoding: Decode and inspect any JWT to see its contents
  • Opaque Token Demo: Generate, validate, and revoke opaque tokens
  • Interactive Learning: See the differences between token types in action
  • Visual Comparison: Side-by-side comparison of token characteristics

📚 Educational Content

What are JWTs?

JSON Web Tokens (JWTs) are an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. JWTs consist of three parts:

  1. Header: Contains metadata about the token type and signing algorithm
  2. Payload: Contains the claims or data being transmitted
  3. Signature: Verifies the token hasn't been tampered with

JWTs are encoded, not encrypted, meaning anyone can decode and read the contents, but only those with the secret key can verify the signature.

What are Opaque Tokens?

Opaque tokens are random strings that have no meaning to the client. Unlike JWTs:

  • They cannot be decoded or inspected by the client
  • They must be validated by checking against a server-side database
  • They can be instantly revoked
  • They don't expose any data to the client

When to Use Each Type

Token Type Best For Advantages Disadvantages
JWT Stateless auth, distributed systems Self-contained, no database lookups Difficult to revoke, payload size affects token size
Opaque High-security operations, sessions requiring revocation Can be instantly revoked, no data exposure Requires database lookups, stateful

🔧 Installation

# Clone the repository
git clone https://github.com/yourusername/token-explorer.git

# Navigate to the project directory
cd token-explorer

# Install dependencies
npm install

# Start the development server
npm run dev