JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts: Header (algorithm and token type), Payload (claims/data), and Signature (verification). JWTs are commonly used for authentication and authorization in web applications and APIs.

How do I decode a JWT token online?

To decode a JWT token: 1) Copy your JWT token (it looks like xxx.yyy.zzz with three parts), 2) Paste it into the input field, 3) The tool will automatically decode and display the Header, Payload, and Signature sections. You'll also see the algorithm used, expiration time, and all claims.

Is it safe to decode JWT tokens online?

Yes, this tool is safe because all decoding happens in your browser (client-side processing). Your JWT tokens are never sent to any server. However, JWTs often contain sensitive information, so only use tokens from development/testing environments, not production tokens with real user data.

JWT claims are key-value pairs in the payload that carry information. Standard claims include: iss (issuer), sub (subject), aud (audience), exp (expiration time), nbf (not before), iat (issued at), and jti (JWT ID). Custom claims are additional fields you define for your application, like user_id, email, or role.

How do I check if a JWT token is expired?

Our tool automatically checks the "exp" (expiration) claim in your JWT and displays the expiration status with a colored badge. You'll see "Valid" (green) if not expired, "Expired" (red) with how long ago it expired, or "Future Token" (yellow) if the expiration is in the future.

JWT 디버거

JSON Web Token(JWT)을 실시간으로 디코딩하고 검증

JWT 토큰

JWT 토큰을 여기에 붙여넣으세요...

팁

• JWT 토큰을 붙여넣으면 내용을 디코딩하여 확인할 수 있습니다

• 토큰은 헤더(알고리즘), 페이로드(클레임), 서명으로 구분됩니다

• 만료 시간(exp)을 확인하여 토큰이 유효한지 검증하세요

• 이 도구는 시크릿 키나 공개 키로 서명을 검증할 수 있습니다

• HS256/384/512는 시크릿 키, RS256/384/512/ES256/384/512는 공개 키를 사용하세요

• RS256/ES256의 경우 PEM 형식의 공개 키를 붙여넣으세요 (-----BEGIN PUBLIC KEY-----)