Developer Tool

Decode & Inspect
JSON Web Tokens

Paste any JWT to instantly decode its header, payload, and signature — entirely in your browser. Nothing leaves your device.

What is a JWT?

A JSON Web Token is a compact, URL-safe means of representing claims between two parties. Tokens are signed — not encrypted — so their contents are always readable. Never store sensitive secrets inside a JWT payload.

Header
Algorithm & Type
The first segment declares the signing algorithm (e.g. HS256, RS256) and token type. Always "typ": "JWT".
Payload
Claims
The second segment contains claims — statements about the entity. Registered claims like sub, iss, exp have defined meanings.
Signature
Integrity
The third segment proves the token has not been tampered with. Verification requires the secret or public key — this tool only decodes, not verifies.
Security
Privacy Note
All decoding happens locally in your browser. No token data is transmitted to any server. Safe to use with production tokens.