Curl Returns 200 But Wrong Data: Validate API Responses

Your curl command returns HTTP 200, but the response body contains an error or wrong data. Learn how to detect and handle this.

The Problem: HTTP 200 with Wrong Content

Many APIs return HTTP 200 even when there's an error, putting the error in the response body:

JSON APIs return 200 with error object
REST APIs return 200 with HTML error page
GraphQL returns 200 with errors array
Health checks return 200 when service is degraded

Checking only HTTP status code isn't enough. You need to validate response body content.

Solution: Validate Response Body

Always check response content, not just HTTP status. Parse JSON responses and look for error fields, or search for error keywords in text responses.

Bash Example: Check JSON Response

#!/bin/bash
RESPONSE=$(curl -s -w "\n%{http_code}" "https://api.example.com/data")
HTTP_CODE=$(echo "$RESPONSE" | tail -n1)
BODY=$(echo "$RESPONSE" | sed '$d')
# Extract response validation data
HAS_ERROR=0
if echo "$BODY" | grep -q '"error"'; then
  HAS_ERROR=1
fi
# Single ping with response data in payload
# In DeadManPing panel: set validation rules:
#   - "status_code" == 200
#   - "has_error" == 0
# Panel will automatically detect violations and alert
curl -X POST "https://deadmanping.com/api/ping/api-check?status_code=$HTTP_CODE&has_error=$HAS_ERROR"

Python Example: Validate JSON

import requests
import json
response = requests.get("https://api.example.com/data")
# Extract response data for payload
has_error = False
try:
  data = response.json()
  has_error = "error" in data
except json.JSONDecodeError:
  has_error = True  # Invalid JSON
# Single ping with response data in payload
# In DeadManPing panel: set validation rules:
#   - "status_code" == 200
#   - "has_error" == False
# Panel will automatically detect violations and alert
requests.post(f"https://deadmanping.com/api/ping/api-check?status_code={response.status_code}&has_error={has_error}")

Monitoring Response Validation

After adding response validation to your scripts, use a dead man switch to monitor whether validation completed successfully. If your script detects wrong data and exits with error code, the ping never arrives, and you get an alert.

Working Examples

See complete, working code examples in our GitHub repository:

View Examples on GitHub →

Start Validating API Responses

DeadManPing monitors whether your response validation completes. Set up monitoring in 2 minutes, get alerts when APIs return wrong data.

Start Monitoring Free

Learn more about cron job monitoring and troubleshooting:

Curl Returns 200 But Wrong Data: Validate API Responses

The Problem: HTTP 200 with Wrong Content

Solution: Validate Response Body

Bash Example: Check JSON Response

Python Example: Validate JSON

Monitoring Response Validation

Working Examples

Start Validating API Responses

Related Articles

Curl Success But Wrong Response

Verify Cron Output

Verify Script Output Content

Cron Job Returns Success But Fails