Pass a JWT token and get a boolean if the token is valid, the requirements for a valid token are defined by the official RFC 7519 standard

npm

npm install is-jwt-valid

yarn

yarn add is-jwt-valid

isJwtValid(JWT_TOKEN<STRING>)

isJwtValid('this is no valid token') // returns false
isJwtValid('some.valid.token')   // returns true

Browser Under the hood it uses the window.atob() native feature which is supported in each major browser and IE from version 10 (check mozilla dev site)

Node Uses the native Buffer API from node (check node documentation)