JWT Decoder

Decode and inspect the header and payload of a JSON Web Token.

How to use

1. Paste a JWT into the box.
2. The header and payload are decoded and pretty-printed instantly.
3. Expiry, issued-at and not-before claims are shown as readable dates.

Features

• Fully client-side — the token never leaves your browser
• Header and payload pretty-printed
• Human-readable exp/iat/nbf with an “expired” warning

Good to know

• This tool decodes only — it does not verify the token’s signature.