JWT Debugger

Decode and inspect JSON Web Tokens

Encoded Token

Waiting for input...

Security Note

Tokens are decoded purely client-side. We do not validate signatures or store any data. Never share your secret keys.

HEADER

Algorithm & Token Type

{
  "alg": "...",
  "typ": "JWT"
}

PAYLOAD

Claims & Data

{
  "sub": "...",
  "name": "...",
  "iat": 0
}

SIGNATURE

Verification

ALGORITHM(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload),
  secret
)

About JWT Debugger

Debug and validate JSON Web Tokens (JWT) directly in your browser without compromising security. Your keys and tokens never leave your device. Inspect headers, payload data, and verify signatures with an intuitive, color-coded interface.

This tool is designed to run entirely in your browser. We prioritize your privacy and speed, ensuring a seamless local development experience without any server-side latency or data persistence risks.

Key Features

Client-side only processing for maximum security
Color-coded token parts (Header, Payload, Signature)
Timestamp conversion to human-readable dates
Signature verification support
One-click format and copy
Support for common algorithms (HS256, RS256, etc.)