🔐 JWT Encoder & Generator
Create and sign JWT (JSON Web Tokens) with custom headers, payloads, and signatures. Support for HS256, HS384, HS512 algorithms. Perfect for testing authentication, API development, and security implementations.
🔑 Algorithm & Secret
Header
Encoded
Payload
Encoded
📚 JWT Structure
Header
Contains token type (JWT) and hashing algorithm (HS256, HS384, HS512)
.
Payload
Contains claims (user data, permissions, expiration, etc.)
.
Signature
Verifies token integrity using secret key + algorithm
📖 Common JWT Claims (RFC 7519)
iss (Issuer): Who issued the token
"iss": "https://example.com"
sub (Subject): User/subject identifier
"sub": "user123"
aud (Audience): Intended recipient
"aud": "https://api.example.com"
exp (Expiration): Unix timestamp expiry
"exp": 1735689600
iat (Issued At): Unix timestamp created
"iat": 1704067200
nbf (Not Before): Unix timestamp valid from
"nbf": 1704067200
jti (JWT ID): Unique token identifier
"jti": "abc123-def456"
📝 Quick Examples
⚠️ Security Best Practices
- Strong Secrets: Use random secret keys at least as long as the hash output (32 bytes for HS256, 48 for HS384, 64 for HS512)
- HTTPS Only: Always transmit JWTs over HTTPS
- Short Expiration: Set reasonable exp times (15min - 1 hour)
- Never Share Secrets: Keep secret keys confidential
- Validate Always: Always verify JWT signature on the server
- Sensitive Data: Don't store passwords or secrets in payload
- Refresh Tokens: Use refresh tokens for long sessions
ℹ️ About JWT Encoder
- Create JWTs: Generate signed JSON Web Tokens
- 3 Algorithms: HS256, HS384, HS512 (HMAC-based)
- Custom Payloads: Add any claims and data
- Secret Management: Generate random secrets or use your own
- Verification: Built-in token verification
- Standards Compliant: Follows RFC 7519 specification
💡 Note: This tool runs entirely in your browser. Tokens and secrets never leave your device.
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About JWT Encoder & Generator
Professional tool for generating JSON Web Tokens (JWT). Create signed tokens with custom headers, flexible payloads, and secure signatures for authentication and authorization systems.
Features
- Multiple Algorithms: Supports HS256, HS384, and HS512 for signing tokens
- Custom Headers: Modify JWT header fields to fit your needs
- Flexible Payloads: Add any claims and custom data
- Secret Generator: Create cryptographically secure secrets
- Quick Claims: Add standard claims with one click
- Token Verification: Instantly verify generated tokens
- Copy & Download: Easily export tokens for integration or testing
Use Cases
- API Development: Generate tokens for testing APIs
- Authentication: Create secure user session tokens
- Authorization: Generate tokens with specific permissions
- Testing: Verify JWT validation in your applications
- Learning: Understand how JWTs and claims work