JWT 디코더
무료 JWT 디코더. JSON 웹 토큰을 디코딩하여 헤더와 페이로드를 검사합니다. 토큰은 브라우저를 벗어나지 않습니다. OAuth, 인증 디버깅, API 통합용.
Runs in your browserUpdated Apr 26, 2026
JWT Token
Header
Payload
자주 묻는 질문
›Does this verify the JWT signature?
No — the decoder shows header and payload only. Signature verification requires the issuer's secret or public key, which we never receive.
›Is my token sent to your servers?
Never. Decoding runs entirely in your browser — tokens stay on your device.
›What algorithms are supported?
Any JWT can be decoded (HS256, RS256, ES256, etc.) — decoding is algorithm-agnostic. Verification is the algorithm-specific step.
›What does each part of a JWT contain?
Header: algorithm and token type. Payload: claims (sub, iat, exp, custom data). Signature: HMAC or signature over header.payload using a secret/key.
›Is the decoder free?
Yes — fully free, no signup.