Getting Started
Core Concepts
Introduction to JWT
What is JWT?
JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. JWTs are commonly used for authentication and information exchange in web development.
Compact
Can be sent through URL, POST parameter, or HTTP header. Fast transmission and processing.
Self-contained
Contains all necessary information about the user, eliminating database queries.
Secure
Digitally signed to ensure data hasn't been tampered with during transmission.
Token Structure
Header
Contains metadata about the token
{
"alg": "HS256",
"typ": "JWT"
}Common Use Cases
Authentication
Once the user is logged in, each subsequent request will include the JWT, allowing the user to access routes, services, and resources that are permitted with that token.
Information Exchange
JWTs can be used to securely transmit information between parties. The signature ensures the sender is who they say they are and the content hasn't been tampered with.
Security Considerations
Best Practices
✓ Use HTTPS for token transmission
✓ Implement token expiration
✓ Use strong secret keys
Common Mistakes
✗ Storing sensitive data in payload
✗ Using weak secret keys
✗ Not validating tokens properly