JWT Tokens: How to Decode, Encode, and Validate
JSON Web Tokens (JWT) are the industry standard for authentication and information exchange. Our JWT Decoder and JWT Validator tools help you inspect, create, and validate tokens securely.
What Is a JWT Token?
A JWT (JSON Web Token) is a compact, URL-safe token that consists of three parts: a header (containing the algorithm and type), a payload (containing claims), and a signature (for verification).
How to Decode a JWT Online
Use our JWT Decoder to instantly decode any JWT token and view its header, payload, and signature. The tool works entirely client-side for maximum security.
How to Encode a JWT
Need to create a JWT? Our JWT Encoder generates signed JWT tokens with HS256 or HS512 algorithms from your JSON payload.
How to Validate a JWT
Our JWT Validator performs comprehensive validation including:
- Signature verification against your secret key
- Expiration (exp) claim checking
- Not Before (nbf) claim validation
- Issuer (iss), audience (aud), and subject (sub) verification
JWT Security Best Practices
Always validate tokens on the server side. Never expose your JWT secret key. Use short expiration times and implement token refresh flows for production applications.
Frequently Asked Questions
Is it safe to decode JWT online?
Yes. Our JWT decoder processes everything in your browser. The token never leaves your machine.
What algorithms are supported?
HS256 (HMAC with SHA-256) and HS512 (HMAC with SHA-512) are supported for both encoding and validation.
Use our free JWT decoder or JWT validator now.