JWT Decoder Online Free
Decode and debug JSON Web Tokens instantly. View header, payload, signature and ...Decode and debug JSON Web Tokens instantly. View header, payload, signature and check expiration times. 100% client-side - your tokens never leave you...
Decoder Features
Why Use JWT Decoder Online Free?
Instant Decode
Paste any JWT and see header, payload, and signature decoded instantly with syntax highlighting.
Expiration Check
Automatically detects exp claim and shows if your token is valid, expiring soon, or already expired.
100% Private
All decoding happens in your browser. Your JWT tokens never leave your device - unlike jwt.io.
Detailed Claims
Explains each standard claim (iss, sub, aud, exp, iat) with descriptions and human-readable timestamps.
Common Uses for JWT Decoder
API Debugging
Inspect JWT tokens from API responses to debug authentication and authorization issues.
Security Auditing
Check token claims, expiration times, and algorithms to verify security configuration.
Development
Decode tokens during development to verify payload contents and claim structures.
Expiration Monitoring
Check if tokens are expired or about to expire to troubleshoot authentication failures.
How It Works
Paste Your JWT Token
Copy your JSON Web Token from your application, API response, or browser cookies and paste it in the input field.
View Decoded Header and Payload
Instantly see the decoded header (algorithm, token type) and payload (claims like sub, exp, iat) with human-readable timestamps.
Check Expiration and Copy Data
See if your token is expired, expiring soon, or valid. Copy individual parts with one click for debugging.
Tips & Security Notes
JWT Structure
A JWT has three parts separated by dots: Header.Payload.Signature. The header and payload are Base64-encoded JSON.
Check Expiration First
When debugging auth issues, always check the 'exp' claim first - expired tokens are the most common cause of 401 errors.
Security Note
JWT payloads are encoded, not encrypted. Never store sensitive data (passwords, credit cards) in JWT claims.