A JWT (JSON Web Token) is a compact, URL-safe token format for securely transmitting information between parties. It consists of three parts: header (algorithm), payload (claims/data), and signature. JWTs are the standard for API authentication.

Is it safe to decode a JWT?

Decoding a JWT reveals its contents but does not compromise security — the payload is base64-encoded, not encrypted. The security lies in the signature verification. However, never expose JWTs containing sensitive data in URLs or client-side logs.

Claims are statements about the user and metadata. Standard claims include: iss (issuer), sub (subject), exp (expiration), iat (issued at), and aud (audience). Custom claims can contain any application-specific data like user roles.

How long should a JWT token last?

Access tokens should expire in 15-30 minutes for security. Refresh tokens can last 7-30 days. Short-lived access tokens limit damage if compromised, while refresh tokens provide a smooth user experience without frequent re-authentication.

Veszélyes ide beilleszteni a tokenemet?

Nem! A munkaidő alatt az oldal JavaScript-alapú, ami azt jelenti, hogy sosem küldjük tovább a szerverre az adataidat.

Mit jelent a token lejárata?

A 'exp' (expiration) érték jelöli az időpontot, amikor a token lejár. Egy biztonságos szerver a lejárat után megtagadja a belépést.

🎫 JWT Dekódoló

JSON Web Tokenek (JWT) dekódolása a fejléc (header), törzs (payload) és aláírás (signature) vizsgálatához.

Decodes JSON Web Tokens showing header, payload, and signature without requiring the secret key, for debugging auth flows.

Key Facts

Standardized in RFC 7519 (2015)
80%+ of modern APIs use JWT
Three parts separated by dots (.)
Common algorithms: HS256, RS256

Frequently Asked Questions

What is a JWT?

Compact, URL-safe token with header (algorithm), payload (claims), and signature for API authentication.

Is decoding JWT safe?

Yes — payload is base64-encoded, not encrypted. Security is in signature verification, not content hiding.

What are JWT claims?

Statements about user: iss (issuer), sub (subject), exp (expiration), iat (issued at), aud (audience).

How long should JWT last?

Access tokens: 15-30 min. Refresh tokens: 7-30 days. Short-lived limits damage if compromised.

🎫 JWT Dekódoló

Mi is az a JSON Web Token (JWT)?

JWT felépítése

Gyakori Kérdések

Key Facts

Frequently Asked Questions

🎫 JWT Dekódoló

Mi is az a JSON Web Token (JWT)?

JWT felépítése

Gyakori Kérdések

Key Facts

Frequently Asked Questions

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