JWT Decoder
Decode and inspect any JWT token. View header, payload, and signature in formatted JSON. Security analysis, expiration check, claims inspector — 100% client-side.
Paste your JWT token
100% client-side — your token is never sent anywhere
About JWT Decoding
A JWT is made of three Base64url-encoded parts separated by dots: header.payload.signature. The header and payload are plain JSON — anyone can decode them. The signature is what proves the token was issued by a trusted party.
Never trust a JWT's claims without verifying the signature against the issuer's secret or public key. This tool decodes the token client-side for inspection, but does not verify the signature.