Free JWT Decoder – Decode JSON Web Tokens Online Instantly
By RapidTool Team · Last updated: September 2026
JWT (JSON Web Token) is the standard method for securely transmitting authentication data between parties. Our free JWT decoder lets you instantly inspect the header, payload, and signature of any JWT token — view claims like sub, exp, iat, iss, and aud without needing to write any code.
Standard JWT Claims Explained
sub (Subject) — Identifies the principal, typically a user ID. exp (Expiration Time) — Unix timestamp when the token expires. iat (Issued At) — When the token was issued. iss (Issuer) — Who issued the token. aud (Audience) — Who the token is intended for. nbf (Not Before) — Token not valid before this time. jti (JWT ID) — Unique identifier for the token.
Frequently Asked Questions
Is it safe to paste my JWT token here?
JWT tokens contain Base64-encoded data — they are not encrypted, only signed. The payload is readable by anyone with the token, so there's no additional risk in pasting it into a decoder. However, never share tokens granting access to sensitive resources. Your token is decoded entirely in your browser.
What is the difference between a JWT's header, payload, and signature?
The header contains the token type (JWT) and signing algorithm (HS256, RS256, etc.). The payload contains claims — the actual data. The signature verifies the token wasn't tampered with. A JWT is three Base64url-encoded strings separated by dots (.).
Why does my JWT show as expired?
The exp (expiration) claim is a Unix timestamp. If the current time is past this timestamp, the token has expired. You'll need to obtain a new token by re-authenticating. Check your server's token lifetime settings if tokens expire too quickly.