JWT Decoder — Browser Developer Tool

Developer

JWT Decoder is a browser-based developer tool that decodes jwt header and payload without verifying the signature.

JWT Decoder

Runs in this browserInput is processed only in this browser. It is not sent to or stored on a server.

This only decodes the JWT header and payload. It does not verify signature, expiry, or issuer.

JWT

Header and payload

Next actions

Base64 Encoder and Decoder JSON Formatter and Validator

What is it

JWT Decoder lets you paste code or strings and inspect the result immediately. It is useful for debugging, validation, and encoding tasks without server storage.

JWT = base64url(header).base64url(payload).signature

How to use

1Paste the input.
2Choose a mode if available.
3Read and copy the result.

Reference

JWT Decoder — Browser Developer Tool Reference
Input	Result
sample	decodes JWT header and payload without verifying the signature

Sources & standards

MDN Web Docs: Client-side web APIs - MDN Web Docs
ECMAScript Language Specification - Ecma International

FAQ

Is JWT Decoder input sent to a server?

No. This tool runs in your browser and does not send input to a server.

Can I use JWT Decoder with sensitive values?

It runs in the browser, but avoid pasting tokens or passwords on shared devices or during screen sharing.