JWT Header Payload Signature Explained

Learn how JWT header, payload, and signature work together to secure API communications. This guide explains each component clearly for developers and users.

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What Are JWT Header Payload Signature?

JWT (JSON Web Token) is a compact authentication format containing three parts:

- **Header**: Algorithm and token type

- **Payload**: Claims (data) about the user

- **Signature**: Security proof of authenticity

These components work together to create tamper-proof tokens for secure API communication.

Understanding JWT Header

The header defines the signing algorithm and token type. It includes:

- Encryption algorithm (e.g., HMAC SHA256)

- Token format specification

Example header: `{"alg": "HS256\