JWT Decoder

Decode, analyze and verify JSON Web Tokens, view detailed information of header, payload and signature

9 uses | 5.0 rating

Input JWT

Validation Options

Instructions

1

Enter JWT Token

Paste the JWT token you want to decode into the input box, or click the "Sample JWT" button to load a sample token.

2

Select Validation Options

Choose whether to perform signature validation and enter the HMAC key as needed.

3

Decode JWT

Click the "Decode JWT" button to view the decoded results and detailed information.

4

Analyze Results

View the JWT header, payload, and signature information, as well as the token's validity status.

JWT Basic Knowledge

What is JWT?

JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information. It is a compact and self-contained token used to securely transmit information between parties as a JSON object.

JWT Structure

Header

Contains token type and signature algorithm information

{
  "alg": "HS256",
  "typ": "JWT"
}

Payload

Contains claim information such as user identity, permissions, etc.

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

Signature

Security verification to ensure the token hasn't been tampered with

SflKxwRJSMeKKF2QT4fwp...
Header.Base64UrlEncode() + '.' + Payload.Base64UrlEncode() + '.' + Signature

JWT Use Cases

Authentication

After user login, the server returns a JWT, and clients carry this JWT in subsequent requests for authentication

Authorization

JWT can contain user permission information to control access to resources

Information Exchange

Securely transmit information between different systems, JWT signatures can verify the sender's identity and data integrity

Cross-Domain Authentication

Suitable for authentication needs in Single Sign-On (SSO) and microservice architectures

JWT Standard Claims

声明名称 简写 描述
issuer iss The issuer of the JWT
subject sub The subject of the JWT
audience aud The audience of the JWT
expiration time exp The expiration time of the JWT
not before nbf The time the JWT becomes valid
issued at iat The time the JWT was issued
JWT ID jti Unique identifier for the JWT