JWT Decoder
Client-side only: Tokens are decoded purely in your browser. Signature verification requires your backend secret key and is not performed here.
Header: Algorithm & Token Type
// Header JSON will appear here
Payload: Data & Claims
// Payload JSON will appear here
Free Online JWT Decoder
Paste any JSON Web Token to instantly decode its header, payload, and signature sections into readable JSON. See claims like expiration time, issued-at date, and subject at a glance — all decoded locally in your browser without sending the token anywhere.
What Is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe format commonly used for authentication and authorization. It consists of three Base64Url-encoded parts — header, payload, and signature — separated by dots, letting servers verify a user's identity without repeated database lookups.
Frequently Asked Questions
Find answers to common questions about this tool, data privacy, and usage.
Paste your JWT into the input field and the tool instantly decodes the header and payload sections, displaying them as readable JSON.
