JWT Decoder Online

Decode and inspect JWT tokens instantly. View header, payload and expiry.

🔒 Your token never leaves your browser. Everything is decoded locally.

Invalid JWT token. Please check the format.

What is a JWT Token?

JWT stands for JSON Web Token. It is an open standard for securely transmitting information between two parties as a JSON object. JWTs are commonly used for authentication and authorization in web applications and APIs.

JWT Token Structure

A JWT token has three parts separated by dots. Each part is Base64URL encoded.

header.payload.signature

What Each Part Contains

Header — Algorithm type and token type

Payload — Claims data such as user ID, roles, and expiry time

Signature — Verifies the token has not been tampered with

Is It Safe to Decode a JWT?

Decoding a JWT only reads the header and payload — it does not verify the signature. The payload data is Base64 encoded, not encrypted, so it can be read by anyone. Never put sensitive data like passwords inside a JWT payload. This tool decodes entirely in your browser — no data is sent to any server.