Free Online JWT Decoder Tool
Analyze and decode JSON Web Tokens (JWT) instantly. Our tool helps you inspect and validate JWT contents, verify signatures, and understand token claims using common algorithms like HS256 and RS256.
Essential for API testing, debugging authentication issues, and security analysis. All decoding happens securely in your browser - your tokens and secrets never leave your device.
How to Decode JWTs in 3 Steps
- Paste your JWT - Enter the complete token you want to analyze
- Enter your secret/key - Optional: add key to verify the signature
- Click "Decode JWT" - View header, payload, and signature validation
JWT Decoder Features
- Multiple algorithm support - HS256, HS384, HS512, RS256 verification
- Visual claim analysis - Human-readable formatting of payload data
- Expiration checking - Automatic validation of exp, nbf, and iat claims
- Secure processing - All decoding happens client-side
Common JWT Decoder Use Cases
- Debug authentication - Validate tokens during development
- Inspect API tokens - Analyze access and refresh tokens
- Security auditing - Verify token contents and claims
- User troubleshooting - Check for expired or malformed tokens
Why Use JWT Decoding?
Development Benefits
- Identify token structure and payload issues quickly
- Verify proper signing and algorithm usage
- Understand token lifetimes and expiration behavior
Security Advantages
- Client-side processing ensures token privacy
- Validation helps detect tampering attempts
- Confirm proper implementation of JWT standards