DEV Community

Manisha Batesar
Manisha Batesar

Posted on

What is JWT?

JWT (JSON Web Token)is a token (like a small digital key) that the backend creates after a user logs in.
👉 It tells the server: “Yes, this user is already logged in.”

We can think of JWT like an ID card or an entry pass.

Why use JWT?

Without JWT: you’d have to send your password every time — unsafe and slow.

With JWT: login once, get a token, and send it with every request. The server checks it and allows access.

JWT is made of three parts:

Header: token type & algorithm

Payload: user info (never store passwords)

Signature: secret key that proves the token is real

How it works:

👉 User logs in → server creates JWT
👉 Token sent to frontend → stored (usually in localStorage)
👉 User makes requests → token sent in headers
👉 Server checks token → allows or denies access

Thanks for reading!❤️

Top comments (0)