JWT Decoder

Decode JSON Web Tokens to view header, payload, and signature as formatted JSON. Checks token expiration. All processing happens in your browser.

Key features

Decode JWT header and payload to readable JSON
Check token expiration with visual expired/valid badges
Color-coded JWT parts for easy identification
No server required - everything happens in your browser

Guide

JSON Web Tokens (JWTs) are the most widely used token format for authentication and authorization in modern web applications. They appear in Authorization headers, OAuth flows, single sign-on systems, API gateways, mobile app sessions, and microservice communication. This tool decodes JWT tokens and displays their header, payload, and signature information in a readable format. ## What a JWT Is A JWT is a compact, URL-safe string that represents a set of claims (assertions about a user or system). It consists of three parts separated by dots: header.payload.signature. Each part is Base64URL-encoded. The header is a JSON object that specifies the token type and signing algorithm. A typical header looks like {"alg":"RS256\

Frequently asked questions

What is a JWT?

A JSON Web Token is a compact, URL-safe way to represent claims between parties. It has three parts: header, payload, and signature.

Is it safe to paste my JWT here?

Yes. Everything is processed in your browser. No data is sent to any server.