JWT Debugger

Free JWT Debugger. Decode JSON Web Tokens online, verify signatures client-side, and format timestamps (exp, iat). Secure and stateless.

Note: Signature verification is not performed. All operations are done client-side.
HeaderALGORITHM & TOKEN TYPE
// Header content
PayloadDATA
// Payload content
SignatureVERIFICATION
HMACSHA256( base64UrlEncode(header) + "." + base64UrlEncode(payload), your-256-bit-secret )

Main Features

  • โœ“Decode Header & Payload
  • โœ“Readable Date Format (exp, iat)
  • โœ“Client-side processing only

How to use

  1. 1

    Paste your JWT token string.

  2. 2

    View the decoded Header and Payload.

  3. 3

    Check the expiration date.

Learn More

What is JWT?

Imagine a digital 'stamped ticket' or a 'secure ID card'. It's a way for a website to give you a pass that proves who you are (e.g., 'I am User 123'). This pass is safe because it has a digital signature that prevents tampering.

Why use it?

Privacy and Speed. The server doesn't need to check its main database every time you click a page. It just looks at your 'ticket' (the token) to see if it's valid. This makes websites faster and allows you to stay logged in easily.

How it works

The token has 3 parts: 1) Header (Introduction), 2) Payload (Your ID and info), and 3) Signature (The security stamp). When you log in, the server gives you this token. You attach it to your requests, and the server verifies the stamp to let you in.