Our JWT Debugger is a secure and simple tool that helps you decode, verify, and check JSON Web Tokens (JWT) in seconds. Whether you're debugging an authentication issue or need to create a test token, this tool gives you a clear view of your token's header, payload, and signature. Your data stays 100% private because all processing happens entirely in your browser.

Key Features & Benefits

Instant Decoding

Quickly unpack your token's Base64 header and payload into a readable JSON format without any setup.

Check Expiration

We automatically check the 'exp' claim in your token to let you know exactly when it expires and if it's still active.

Create Test Tokens

Sign your own tokens for local development using your secret key and custom payload data.

100% Private & Secure

Your secret keys and payloads never leave your computer. We process everything in your browser for total privacy.

How to Use the JWT Debugger & Decoder - Free Online JWT Tool

Paste Your Token

Simply paste your JWT into the input box. Our tool will immediately decode it and show you the details.

Check the Details

Easily view the header and payload of your token. We'll also tell you if the token has expired and if the structure is valid.

Create a New JWT

Switch to 'Create' mode to build your own token. Enter your header, payload, and secret key to generate a new signed JWT instantly.

Copy or Download

Copy your decoded data or generated token to your clipboard, or download a full analysis as a JSON file.

Practical Use Cases

Debugging Login Issues

Check why a user's session isn't working by inspecting the token's claims and expiration time.

API Development

Create and test different tokens to see how your backend handles various roles and custom attributes.

Security Auditing

Quickly verify that your authorization tokens contain the correct information and haven't been tampered with.

Learning JWT

Understand how JSON Web Tokens work by experimenting with different headers and payloads in a secure environment.

FAQs

What is a JWT token?

JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties as a JSON object.