Question 1

What is a JWT?

Accepted Answer

JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. It consists of three parts: header, payload, and signature, separated by dots.

Question 2

How to decode a JWT?

Accepted Answer

Split the JWT by dots into header, payload, and signature. Base64url-decode the header and payload to get JSON. The signature is binary and cannot be decoded as text.

Question 3

Can I verify JWT signature in browser?

Accepted Answer

Yes. For HS256, you can verify using the Web Crypto API with the shared secret. For RS256/ES256, you need the public key in PEM or JWK format.

🔐 JWT Decoder

Encoded JWT

Token Status

Decoded Payload

Registered Claims

Verify Signature (HS256)

Recent Tokens