- Step 1: Select Operation Mode - Choose 'JWT Decoder' to analyze an existing token or 'JWT Encoder' to create a new one.
- Step 2: Decoder Mode - Paste a JWT token, and the tool will automatically parse and display the header and payload. Enter a secret to verify the signature.
- Step 3: Encoder Mode - Edit the header (select algorithm) and payload (add claims), then enter a secret to automatically generate the JWT.
- Step 4: Use the Result - Copy the generated token for use in your application, or review the decoded information for debugging and validation.
What is a JWT (JSON Web Token)?
A JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties as a digitally signed JSON object. JWTs consist of three parts: header, payload, and signature. They are commonly used for authentication and authorization in web applications and APIs.
Is JWT Generator free to use?
Yes, JWT Generator is completely free to use with no registration required. You can generate, decode, and verify unlimited JWT tokens without any cost. All features including secret key generation and signature verification are available at no charge.
Is my data safe with JWT Generator?
Yes, your data is completely safe. All JWT generation and decoding happens entirely in your browser - no data is sent to our servers. Your secret keys and token contents remain private and are never stored or transmitted anywhere.
What are the common use cases for JWT?
JWTs are primarily used for user authentication and API authorization. Common use cases include maintaining session state without server-side storage, protecting REST APIs and microservices, implementing Single Sign-On (SSO), and enabling secure communication between services.
Which JWT algorithms do you support?
We support the most common HMAC-based JWT signing algorithms: HS256 (HMAC SHA-256), HS384 (HMAC SHA-384), and HS512 (HMAC SHA-512). These symmetric algorithms use a shared secret key for both signing and verification.
What are some JWT security best practices?
Always use strong, randomly generated secrets with sufficient length. Set appropriate expiration times using the exp claim. Never store sensitive information like passwords in the payload. Validate JWT signatures server-side and use HTTPS to prevent token interception.
What are the standard JWT claims?
Standard JWT claims include: iss (Issuer), sub (Subject), aud (Audience), exp (Expiration Time), nbf (Not Before), iat (Issued At), and jti (JWT ID). These predefined claims ensure interoperability between different JWT implementations.
JWT: Claims, Signatures, Encryption & Verification
Understand JWT structure without confusing encoding, signing, encryption, or authorization. This guide covers algorithm allowlists, issuer/audience/expiry validation, browser storage and CSRF, refresh-token rotation, revocation, JWS/JWE, and safe JavaScript, Python, and Java boundaries.
JWT Signing Keys【2026】: Generate, Store, Rotate, and Verify Them Safely
A security-focused guide to JWT signing keys. Learn the boundary between JWT, JWS, HMAC, and encryption; generate HS256/HS384/HS512 secrets with a local CSPRNG; choose RSA, EC, or EdDSA keys; verify claims and algorithms; and design storage, rotation, revocation, and incident response without treating JWT as authorization.
Bearer Tokens: JWT, OAuth, Storage & Revocation
Understand Bearer Tokens without confusing the transport scheme with JWT or OAuth. This guide covers issuer, audience, scope and tenant validation, TLS, browser storage and CSRF, refresh-token rotation, revocation, algorithm policy, and framework boundaries.
JWT
JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is digitally signed using a cryptographic algorithm.
Bearer Token
Bearer Token is an access token type used in HTTP authentication where the client presents a token to access protected resources. The term 'bearer' means that any party holding the token can use it to access the resource, without needing additional proof of identity.