What does "JWT" mean in programming?

JWT is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.

Definition

JSON Web Token. A compact, self-contained token format used to securely transmit information between parties as a JSON object. A JWT has three parts: header, payload, and signature. It is widely used for authentication: the server issues a JWT after login and the client sends it with every request.

Example

"The JWT expires after 1 hour. After expiry, the client must refresh it using the refresh token."

Related terms

OAuth
SSO
authentication
token
session

Ready to practice your English at work?

Lingua-e has interactive exercises built around real developer conversations: standups, code reviews, retrospectives, and more. Practice until it comes naturally.

Try Lingua-e for free