OpenTools
JWT Inspector

JWT Inspector API

Security

Decode and analyze JSON Web Tokens instantly. Validate JWT tokens, check expiration, and inspect claims for secure authentication workflows.

Authentication

All API requests require a valid API key passed in the Authorization header as a Bearer token.

Rate Limit

100 requests per minute

Endpoints

1 endpoint available

Overview

The JWT Inspector API decodes and analyzes JSON Web Tokens, extracting header, payload, and signature information.

Features

  • Decode JWT tokens (3-part dot-separated format)
  • Extract header with algorithm (alg) and type (typ)
  • Parse payload with standard claims (iss, sub, aud, exp, nbf, iat, jti)
  • Check expiration status (valid/expired)
  • Format timestamps to human-readable dates

Use Cases

  • Debug authentication issues in APIs
  • Validate token claims programmatically
  • Check token expiration before processing
  • Inspect tokens in automated testing

Endpoints

POST
/v1/tools/jwt-inspector
Decode and analyze a JWT token

Request Body

Content-Type: application/json

ParameterTypeRequiredDescription
token
string
Required
The JWT token to decode (must have 3 parts separated by dots)

Response Example

{
  "success": true,
  "data": {
    "header": {
      "alg": "HS256",
      "typ": "JWT"
    },
    "payload": {
      "sub": "1234567890",
      "name": "John Doe",
      "iat": 1516239022,
      "exp": 1716239022
    },
    "signature": "SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c",
    "isExpired": false,
    "expiresAt": "2024-05-21T00:23:42.000Z",
    "issuedAt": "2018-01-18T01:30:22.000Z"
  }
}

Error Codes

400
Bad Request - Invalid JWT format (must have 3 parts)
401
Unauthorized - Invalid or missing API key
429
Too Many Requests - Rate limit exceeded
500
Internal Server Error

Code Examples

curl -X POST https://api.opentools.ca/v1/tools/jwt-inspector \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c"
  }'

Ready to get started?

Create an API key to start using the JWT Inspector API.