UtiLive.dev
Fast, privacy-friendly developer utilities
JWT Debugger
Decode and verify JSON Web Tokens locally. No data leaves your browser.
Features
•
Token Decoding:
Decode JWT headers and payloads without verification
•
Signature Verification:
Verify tokens with various key types
•
Multiple Algorithms:
Support for HS256, RS256, and ES256
•
Key Formats:
HMAC secrets, PEM keys, and JWK
•
Local Processing:
All operations happen in your browser
Supported Algorithms
HS256
HMAC with SHA-256
Symmetric
RS256
RSA with SHA-256
Asymmetric
ES256
ECDSA with SHA-256
Asymmetric
Sample JWTs
Show Examples
JWT Token
Token
Verification Options
Verification Mode
Decode only
HMAC Secret (HS256)
Public Key (SPKI PEM)
Private Key (PKCS8 PEM)
JWK (JSON)
Algorithm
HS256
RS256
ES256
Decoded Payload
Verification Result
Provide a key to verify token.
JWT Structure
Header
•
alg
- Algorithm used
•
typ
- Token type (JWT)
•
kid
- Key ID (optional)
Payload
•
sub
- Subject
•
exp
- Expiration time
•
iat
- Issued at
• Custom claims
Signature
• Verifies token integrity
• Prevents tampering
• Algorithm-specific
• Base64URL encoded