JWT Decoder

Decode JWT header and payload without verification.

JWT Token

This tool decodes only. It does not verify the signature — do not trust claims until you validate the token with a proper library.

How to Use

What is a JWT? A JSON Web Token (JWT) is a compact token made of a header, a payload and a signature, each Base64URL-encoded and joined by dots.

How to use it 1. Paste a JWT into the input box. 2. DevToolBox splits it into header, payload and signature. 3. The header and payload are decoded and pretty-printed as JSON.

Tips - Timestamp claims such as `exp`, `iat` and `nbf` are shown as readable dates. - Decoding is for inspection and debugging, not a security check. - Always verify the signature and expiration before trusting a token.

Privacy Decoding happens entirely in your browser.

JWT Decoder — Decode JSON Web Tokens