JWT Decoder Tool

Decode JWT headers and payloads to inspect token contents. Free, secure, and works directly in your browser without a server.

JWT Token

Token Structure

Header
Payload
Signature

Common Claims

iss:
Issuer - identifies the principal that issued the JWT
sub:
Subject - identifies the principal that is the subject of the JWT
aud:
Audience - identifies the recipients that the JWT is intended for
exp:
Expiration Time - identifies the expiration time on or after which the JWT MUST NOT be accepted for processing
nbf:
Not Before - identifies the time before which the JWT MUST NOT be accepted for processing
iat:
Issued At - identifies the time at which the JWT was issued
jti:
JWT ID - provides a unique identifier for the JWT

Decoded Header

Decoded Payload

Token Validation

Signature Verification

Not verified

Client-side verification is not possible without the secret key. This tool only decodes the token.

Token Expiration

Unknown

Algorithm Information

Algorithm:
Unknown

How to use JWT (JSON Web Token) Decoder

  1. Enter or paste your JWT string into the input field.
  2. Click the 'Decode' or 'Inspect' button to process the token.
  3. View the decoded header and payload sections in a structured format.
  4. Copy the decoded information for your records or debugging.

Features

  • Supports standard JWT format with header, payload, and signature sections.
  • Instantly decodes and displays token contents without requiring a secret key.
  • Presents decoded JSON in a human-readable, formatted view for easy inspection.
  • Works directly in your browser, requiring no server-side processing or uploads.
  • Useful for debugging authentication flows and verifying token claims.

Who Is This Tool For?

Essential for developers, security engineers, and API testers who need to inspect the contents of a JWT during development, debugging, or security auditing.

Why Decode a JWT?

Decoding a JWT is a fundamental step for developers to verify the claims, expiration, and issuer of a token, ensuring proper authentication and authorization in modern web and API security workflows. It allows for immediate inspection of embedded user data and token metadata without relying on backend services.

Frequently Asked Questions

Is this JWT decoder free to use?

Is my JWT token sent to a server?

What parts of a JWT can this tool decode?

Does this tool validate the JWT signature?

What format does the decoded output use?

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