JWT Decoder & Debugger
Decode JSON Web Tokens instantly. 100% client-side, your tokens never leave your browser.
About the JWT Decoder & Debugger
The JWT Decoder by Grab-Kit is a free online tool designed for backend developers, security engineers, and API integrators. JSON Web Tokens (JWT) are the standard for stateless authentication in modern web apps. They contain a Header (metadata), a Payload (user data), and a Signature. Because the token is just a Base64Url encoded string, it's unreadable to humans. Our tool instantly decodes this string into readable JSON.
Using the tool is incredibly straightforward and secure. Paste your JWT into the input box. The tool instantly splits the token by its dots, decodes the Header and Payload, and displays them as formatted, color-coded JSON. It also extracts the algorithm (like HS256 or RS256) and reads the exp (expiration) claim to tell you exactly when the token will expire and if it is currently valid or expired. Best of all, the decoding happens entirely in your browserâyour sensitive authentication tokens are never transmitted over the network.
Why use Grab-Kit?
All our tools run entirely in your browser using native JavaScript. This means zero latency and 100% privacy for your sensitive data. It is completely free, requires no signup, and works flawlessly on both desktop and mobile devices, making it the perfect utility for your development and debugging workflow.