How to decode a JWT

A JWT is three Base64 parts. Here's how to decode one to inspect its claims — safely and without a library.

Open JWT Decoder

Steps

  • Open the JWT decoder and paste your token.
  • The header and payload are decoded and shown as readable JSON.
  • Check claims like exp (expiry), iss (issuer) and sub (subject).

Decoding is not verifying

Decoding reveals what a token contains but does not verify its signature. Never trust an unverified token for authorization decisions — verification requires the signing key on your server.

Tools used in this guide

Related guides

How to decode a JWT — FAQ

Paste it into the JWT decoder — it shows the header and payload as JSON so you can inspect the claims.