JWT Debugger & Decoder

Decode JSON Web Tokens (JWT) in real-time, inspect headers, check payloads, and verify expiration dates.

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Paste encoded Token (JWT)

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Decoded JSON Web Token

HEADER: ALGORITHM & TOKEN TYPE alg, typ 
{ ... }
PAYLOAD: DATA / CLAIMS sub, iat, exp 
{ ... }

Quickly decode JWT headers and payload claims locally in your browser. Automatically parses timestamps, displays claim details, and color-codes JSON structures for flawless debugging.

JWT Debugger & Decoder Guide

Decode JSON Web Tokens (JWT) instantly. Inspect headers, check payloads, and verify expiration dates without exposing secret keys.

How to Decode JSON Web Tokens:

  1. 1

    Paste your encoded JWT string (containing three parts separated by dots) into the token box.

  2. 2

    The decoder automatically splits the token into Header, Payload, and Signature blocks.

  3. 3

    View payload claims, issue dates, expiration times, and algorithm types.

  4. 4

    Check expiration times to see if your token is still valid.

JWT Debugger Capabilities:

Three-Part Breakdown

Color-coded interface separating Header, Payload, and Signature.

Expiration Tracker

Automatically translates Unix timestamps (exp, iat) into local date-times.

Signature Verification Info

Displays algorithm details (HS256, RS256) used to sign the token.

Client-Side Decoding

Decoding is done locally, keeping sensitive payload claims private.

Technical Specifications

Specification Details / Limits
Standard Scope RFC 7519 JWT Standards
Algorithms Supported HS256, HS384, HS512, RS256, RS384, RS512
Data Security 100% Local Decoding, Zero Server Calls

Frequently Asked Questions

What are the three parts of a JWT?

A JSON Web Token consists of three parts separated by dots (`.`): Header (defines algorithm and token type), Payload (contains user claims), and Signature (verifies integrity).

Is a JWT encrypted?

No. Standard JWTs are encoded using Base64URL, not encrypted. Anyone can decode and read the contents of a JWT, so you should never store sensitive data like passwords inside them.

How do I verify a JWT signature?

To verify a JWT signature, take the header and payload, hash them using the algorithm specified in the header and your secret key, and match it against the signature block.