JWT Decoder — Free Online Tool
Decode and inspect JSON Web Tokens (JWT) online for free. View header, payload claims, expiry, and signature section instantly. Never leaves your browser.
🔒 Decoded entirely in your browser. Token never sent to any server.
About JWT Decoder
JSON Web Tokens (JWT) are widely used for authentication and authorisation in web applications and APIs. Our JWT decoder parses any JWT and displays the decoded header (algorithm, token type) and payload (user ID, email, roles, expiry, issued-at, and custom claims) in a readable format. It also shows whether the token has expired, the issuer, audience, and all standard JWT claims. Your token is decoded entirely in the browser — never sent to any server.
Frequently Asked Questions
Is my JWT token safe when using this tool?
Yes — the token is decoded entirely in your browser using JavaScript. It is never transmitted to any server.
Does it verify the JWT signature?
Without your secret key, signature verification is not possible. This tool decodes and displays the payload only.
What information is in a JWT payload?
Standard claims include sub (user ID), iss (issuer), aud (audience), exp (expiry timestamp), iat (issued at), and custom claims.
How do I know if a JWT has expired?
The exp claim is compared to the current time and a clear Expired or Valid status is shown.
What JWT algorithms are supported?
HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, ES512, and PS algorithms are all supported.