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JWT Decoder & Debugger

Decode and inspect JSON Web Tokens (JWT) client-side. View decoded headers, payload claims, and expiration timestamps securely without server logging.

Enter an encoded JSON Web Token on the left to start decoding

What is the JWT Decoder?

The JWT Decoder splits and decodes JSON Web Tokens into structured header and payload JSON objects, displaying expiration metadata and claim parameters cleanly.

How to Use the Tool

  1. Paste your raw encoded JWT string into the editor.
  2. The tool automatically splits Header, Payload, and Signature components.
  3. Inspect human-readable timestamps (exp, iat) and payload claims instantly.

Common Use Cases

  • Debugging authentication tokens in OAuth2 and OpenID Connect flows.
  • Inspecting user roles and permission claims inside payloads.
  • Verifying token expiration times without backend logging.

Supported Formats & Options

Supports standard 3-part encoded JSON Web Tokens (Header.Payload.Signature) with automatic epoch-to-date formatting for standard claims.

Related Guides & Tutorials

Utilities • 5 min read
Understanding JWT Structure: Header, Payload, and Standard Claims

An in-depth developer guide to understanding JSON Web Tokens. Learn the technical structure of the header, payload claims, and signatures.

Read Guide
Security • 4 min read
Understanding Cryptographic Hashing: SHA-256, MD5, and Checksums

Learn what cryptographic hash functions are, how SHA-256 and SHA-512 maintain data integrity, and why hashing is one-way.

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Security • 4 min read
How to Decode and Inspect JSON Web Tokens (JWT)

A complete developer guide to decoding JSON Web Tokens. Learn how JWT headers, payload claims, and signatures work client-side.

Read Guide

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Frequently Asked Questions

Is my JWT secret or payload secure?

Yes. All parsing and base64url decoding occurs 100% locally in your browser. No token data is ever transmitted to our servers.

Does this verify JWT signatures?

This tool parses and inspects the token header and payload claims client-side. Signature verification without exposing your private secret is not required for payload debugging.