JWT Decoder - Decode JWT Online

Outstanding features

What is JWT and why do developers need to decode?

JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties in the form of JSON objects. JWT is widely used for: Authentication - after login, the server returns a JWT containing user information. Authorization - each request is sent with JWT so the server knows what permissions the user has. Information Exchange - transfers digitally signed data. Developers need to decode JWT to: Debug authentication issues - see what the token contains and whether it has expired or not. Verify user claims - check roles, permissions in token. Understand API responses - see what the server returns. Learn JWT structure - understand how JWT works. This tool helps decode quickly without writing code.

Benefits when used

• •Debug authentication quickly
• •Check token expiration visually
• •Understand JWT structure and claims
• •No need to write code to decode
• •Security - tokens are not sent to the server
• •Copy claims to use in code
• •Validate token format
• •Supports all JWT algorithms

How to decode JWT Token

1. 1Copy JWT token from API response, localStorage, or cookies
2. 2Paste the token into the input box (format: xxxxx.yyyyy.zzzzz)
3. 3The tool automatically decodes and displays 3 parts
4. 4See Header: algorithm (alg) and type (typ)
5. 5See Payload: all claims (iss, sub, exp, custom claims...)
6. 6Check exp: whether the token is valid or expired
7. 7See Signature: digital signature (cannot verify client-side)
8. 8Click Copy to copy each part if necessary
9. 9If the token is invalid, see error message for error