Random JWT Token Generator
Generate JSON Web Tokens (JWT) for API authentication, testing, and development with customizable algorithms, claims, and expiration times
[ JWT Token Generator - Quick Summary ]
What: Generate RFC 7519 compliant JSON Web Tokens with algorithms (HS256/384/512, RS256/384/512), custom expiration (1hr-1yr), standard claims (iss, sub, aud, iat, exp, jti), and optional roles/scopes.
When to use: API authentication testing, OAuth/OpenID Connect development, JWT library validation, microservices security testing, stateless session management development.
Example: eyJ0eXAiOiJKV1QiLCJhbGci... (header.payload.signature format, Base64URL encoded)
Security: Testing/development only. Cryptographically signed with HMAC/RSA. Always transmit over HTTPS, use short expirations, validate all claims server-side.
Our JWT token generator creates secure JSON Web Tokens (JWT) for API authentication, OAuth implementations, session management, and microservices security. Generate JWT tokens with configurable signing algorithms (HS256, HS384, HS512, RS256, RS384, RS512), custom expiration times, roles, scopes, and standard claims (iss, sub, aud, iat, exp). Perfect for API security testing, authentication system development, OAuth server testing, and validating JWT parsing libraries. JSON Web Tokens provide stateless authentication using a compact, URL-safe format with three parts: header (algorithm and type), payload (claims about the user), and signature (verification hash). Use our generator for secure JWT creation in API development, authentication testing, microservices authorization, and educational demonstrations of token-based security.
What is a JWT Token Generator?
A JWT (JSON Web Token) generator creates secure, compact tokens for stateless authentication and authorization in modern web applications and APIs. JWTs consist of three Base64URL-encoded parts separated by dots: **header.payload.signature**. The header specifies the signing algorithm (HMAC, RSA, or ECDSA) and token type. The payload contains claims - statements about the user and metadata like issuer (iss), subject (sub), audience (aud), issued-at time (iat), expiration (exp), and custom claims (roles, permissions). The signature ensures integrity by hashing the header and payload with a secret key (HMAC algorithms) or private key (RSA algorithms), preventing tampering and allowing verification without server-side session storage.
Our generator supports industry-standard algorithms: HS256/HS384/HS512 (HMAC with SHA-256/384/512) for symmetric signing using shared secrets, and RS256/RS384/RS512 (RSA with SHA-256/384/512) for asymmetric signing using private/public key pairs. Each generated token includes a cryptographically random secret, configurable expiration (1 hour to 1 year), and standard JWT claims following RFC 7519. Optional role and scope claims enable role-based access control (RBAC) and OAuth-style permission scopes. Use JWT generation for testing authentication flows, developing OAuth/OpenID Connect providers, validating JWT parsing libraries, demonstrating token-based security concepts, and creating realistic test data for API security testing.
JWT Token Generator Configuration
Count (1-10 Tokens)
Algorithm (HS*/RS*)
Expiration Time (1 hour - 1 year)
Include Roles/Scope Claims
How to Generate JWT Tokens
[STEP 1] Configure Token Parameters
Choose count (1-10), signing algorithm (HS256 for shared secrets, RS256 for public/private keys), and expiration time. For API authentication testing, use HS256 with 1 hour expiration. For OAuth/SSO testing, consider RS256 with longer expirations. Select algorithm based on your architecture: symmetric (HS*) for single-server, asymmetric (RS*) for distributed.
[STEP 1] Enable Optional Claims
Check "Include Roles" to add RBAC capabilities with a roles array claim. Check "Include Scope" to add OAuth-style permission scopes. These claims enable fine-grained authorization testing beyond basic authentication. Leave unchecked for minimal tokens with only standard claims (iss, sub, aud, iat, exp, jti).
[STEP 1] Generate & Inspect Tokens
Click EXECUTE GENERATION to create JWT tokens with cryptographically secure secrets. Each token displays with a Copy button for easy clipboard access. Expand "VIEW PAYLOAD & SECRET" to inspect the JSON payload (claims), secret key (for HMAC algorithms), header details, and algorithm. Verify claims include correct timestamps and unique identifiers.
[STEP 1] Use in Testing & Development
Copy tokens for API testing tools (Postman, cURL) by adding "Authorization: Bearer
JWT Token Best Practices
- _ HTTPS Only - Always transmit JWTs over HTTPS/TLS to prevent interception. Tokens sent over HTTP can be stolen via man-in-the-middle attacks. Never embed JWTs in URLs (visible in logs).
- _ Secret Management - Keep signing secrets confidential. For HMAC (HS*), use cryptographically strong secrets (minimum 256 bits). For RSA (RS*), protect private keys and distribute public keys. Rotate secrets periodically.
- _ Short Expiration Times - Use brief exp times for access tokens (15 minutes to 1 hour). Implement refresh tokens for longer sessions. Short expirations limit damage from stolen tokens while refresh tokens enable seamless re-authentication.
- _ Validate All Claims - Server-side verification must check: signature validity, expiration (exp > current time), not-before (nbf ≤ current time if present), issuer (iss matches expected), audience (aud matches your service).
- _ Avoid Sensitive Data in Payload - JWTs are Base64-encoded, not encrypted. Anyone with the token can decode the payload. Never include passwords, credit cards, or PII. Use JWE (JSON Web Encryption) for confidential data.
- _ Token Revocation Strategy - JWTs are stateless and cannot be invalidated until expiration. Implement token blacklisting, maintain short expirations with refresh tokens, or use jti claim for tracking. Consider hybrid approaches combining JWT benefits with revocation capabilities.
Technical Implementation
Our JWT generator follows RFC 7519 specification, creating compact tokens with cryptographically signed payloads ensuring integrity and authenticity:
// JWT Generation Algorithm (RFC 7519)
Algorithm: JSON Web Token Creation with HMAC/RSA Signing
// Step 1: Create Header
header = {
"typ": "JWT",
"alg": algorithm (e.g., "HS256", "RS256")
}
encoded_header = base64url_encode(json_encode(header))
// Step 2: Build Payload with Claims
current_time = unix_timestamp()
payload = {
"iat": current_time (issued at),
"exp": current_time + expires_in (expiration),
"jti": random_uuid_v4() (JWT ID),
"iss": issuer (e.g., "api.example.com"),
"sub": subject (e.g., "user_1234"),
"aud": audience (e.g., "https://example.com")
// Optional: "roles": ["admin", "user"], "scope": "read write"
}
encoded_payload = base64url_encode(json_encode(payload))
// Step 3: Create Signature
unsigned_token = encoded_header + "." + encoded_payload
if (algorithm starts with "HS") then:
secret = random_bytes(32) as hexadecimal (64 chars)
signature = HMAC_SHA(unsigned_token, secret)
else if (algorithm starts with "RS") then:
signature = RSA_SHA(unsigned_token, private_key)
encoded_signature = base64url_encode(signature)
// Step 4: Concatenate Final Token
jwt_token = encoded_header + "." + encoded_payload + "." + encoded_signature
Example: eyJ0eXAiOiJKV1QiLCJhbGc...
// Format: header.payload.signature (Base64URL parts)
Verification: Recalculate signature and compare with provided