Header
Decoded JWT Header content will be displayed here.
{
"alg": "HS256",
"typ": "JWT"
} Payload
Decoded JWT Payload content will be displayed here.
{
"sub": "1234567890",
"name": "John Doe",
"iat": 1516239022
} Signature
JWT Signature content will be displayed here.
SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
Signature Verification
Enter the secret key or public key to verify the JWT signature
How to Use the JWT Debugger
Quick Start
- Paste your JWT into the input field
- JWT decoding happens automatically as you type
- View decoded Header, Payload, and Signature
- Use copy buttons to save decoded content
- Verify signature by entering the secret/public key
JWT Structure
JWTs consist of three base64-encoded parts separated by dots:
- Header: Algorithm and token type
- Payload: Claims and user data
- Signature: Verifies token integrity
Automatic Decoding
The JWT debugger automatically decodes tokens as you type. The algorithm is detected from the token header, and all supported algorithms including HMAC, RSA, ECDSA, and EdDSA are handled seamlessly.