A tool that can help you out to decode JWT tokens, decoded token will be displayed below after a valid token would get processed.
JSON Web Token (JWT) is an Internet standard for creating data with optional signature and/or optional encryption whose payload holds JSON that asserts some number of claims. The tokens are signed either using a private secret or a public/private key.
For example, a server could generate a token that has the claim "logged in as admin" and provide that to a client. The client could then use that token to prove that it is logged in as admin. The tokens can be signed by one party's private key (usually the server's) so that party can subsequently verify the token is legitimate. If the other party, by some suitable and trustworthy means, is in possession of the corresponding public key, they too are able to verify the token's legitimacy.
const token = base64urlEncoding(header) + '.' + base64urlEncoding(payload) + '.' + base64urlEncoding(signature);
Authorization: Bearer eyJhbGci...snip...yu5CSpyHI