JWT Decoder
Decode and inspect JSON Web Tokens. No secret needed — runs entirely in your browser.
About This Tool
Free JWT decoder online — paste any JSON Web Token and instantly decode and inspect the header, payload, and signature in a readable format. 100% client-side: your JWT never leaves your browser. JWT (JSON Web Token) is the standard format for authentication and authorization tokens used by OAuth2, OpenID Connect, and most modern REST APIs. The header identifies the signing algorithm (RS256, HS256, etc.). The payload contains claims: user ID, email, roles, expiry time (exp), issued-at time (iat). The signature verifies authenticity. Developers use this tool to debug login flows, inspect claims returned by an auth provider, check token expiry, and understand what data the backend is reading from a token — without writing a single line of code.
How to Use
- 1
Paste your JWT
Copy a JWT (the three dot-separated Base64 strings) and paste it into the input field.
- 2
Inspect the decoded parts
See the Header (algorithm and type), Payload (claims and data), and Signature (the verification hash) displayed as formatted JSON.
- 3
Check claims
Look at exp (expiry), iat (issued at), and sub (subject/user ID) to verify the token is valid and contains the expected data.