JWT Formatter

JWT Formatter

Decode and format JWT tokens to view header, payload, and signature information.

Benefits of Using JWT Formatter

Token Inspection

Quickly inspect JWT tokens to understand their structure and verify claims without writing code.

Debug Authentication

Easily debug authentication issues by viewing token payloads and expiration times.

Security Analysis

Analyze token structure and claims to ensure proper security implementation.

Privacy Protected

All decoding happens locally in your browser. Your tokens never leave your device.

Key Features

Decode JWT tokens instantly
View header, payload, and signature
Pretty-print JSON payload
Verify token structure
Works entirely offline
Free to use with no limitations

How to Use

1

Paste Your JWT Token

Copy and paste your JWT token into the input field above.

2

Decode Token

Click "Decode" to view the header, payload, and signature information.

3

Inspect Claims

Review the decoded payload to understand the token's claims and expiration time.

Understanding JWT Tokens and Authentication

JWT (JSON Web Token) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.

Our free JWT decoder tool allows developers to inspect and decode JWT tokens instantly. Understanding the structure of JWT tokens is crucial for debugging authentication issues and ensuring proper security implementation.

JWT Token Structure

A JWT token consists of three parts separated by dots (.), which are:

  • Header: Contains metadata about the token, including the type (JWT) and the signing algorithm used (e.g., HS256, RS256).
  • Payload: Contains the claims, which are statements about an entity (typically the user) and additional data.
  • Signature: Used to verify that the sender of the JWT is who it says it is and to ensure that the message wasn't changed along the way.

Common JWT Use Cases

  • Authentication and authorization in web applications
  • Single Sign-On (SSO) implementations
  • API authentication and secure data exchange
  • Stateless authentication for microservices
  • Mobile app authentication

Our tool processes all JWT data locally in your browser, ensuring complete privacy. No tokens are sent to any server, making it safe for sensitive authentication tokens.

Code Examples

JWT Token Example

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

Decoded Header

{
  "alg": "HS256",
  "typ": "JWT"
}

Decoded Payload

{
  "sub": "1234567890",
  "name": "John Doe",
  "iat": 1516239022,
  "exp": 1516242622
}

JWT Claims Example

{
  "iss": "https://example.com",
  "sub": "user123",
  "aud": "api.example.com",
  "exp": 1735689600,
  "iat": 1735686000,
  "roles": ["admin", "user"]
}