API Documentation

Free REST API for unit conversions. No authentication required, no rate limits, completely free to use.

✅ 100% Free 🔓 No Auth Required ⚡ No Rate Limits

Quick Start

Base URL

https://convert-quick.com/api

Example Request

curl -X POST https://convert-quick.com/api/convert/temperature \
  -H "Content-Type: application/json" \
  -d '{"value": 100, "from": "celsius", "to": "fahrenheit"}'

Example Response

{
  "success": true,
  "input": {
    "value": 100,
    "unit": "celsius"
  },
  "output": {
    "value": 212,
    "unit": "fahrenheit"
  },
  "formula": "°F = (°C × 9/5) + 32"
}
POST/api/convert/temperature

Convert temperature units.

Request Body

value(number, required)

The numeric value to convert

from(string, required)

Source unit

to(string, required)

Target unit

Supported Units

celsiusfahrenheitkelvin

Example Request

curl -X POST https://convert-quick.com/api/convert/temperature \
  -H "Content-Type: application/json" \
  -d '{
    "value": 100,
    "from": "celsius",
    "to": "fahrenheit"
  }'

Example Response

{
  "success": true,
  "input": {
    "value": 100,
    "unit": "celsius"
  },
  "output": {
    "value": 212,
    "unit": "fahrenheit"
  },
  "formula": "°F = (°C × 9/5) + 32"
}

Error Handling

400 Bad Request

Invalid request body or unsupported units

{
  "statusCode": 400,
  "message": "Invalid unit. Supported units: celsius, fahrenheit, kelvin"
}

500 Internal Server Error

Unexpected server error

{
  "statusCode": 500,
  "message": "Internal server error during conversion"
}

Code Examples

JavaScript / Node.js

const response = await fetch('https://convert-quick.com/api/convert/temperature', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    value: 100,
    from: 'celsius',
    to: 'fahrenheit'
  })
});

const data = await response.json();
console.log(data.output.value); // 212

Python

import requests

response = requests.post(
    'https://convert-quick.com/api/convert/temperature',
    json={
        'value': 100,
        'from': 'celsius',
        'to': 'fahrenheit'
    }
)

data = response.json()
print(data['output']['value'])  # 212

PHP

$data = json_encode([
    'value' => 100,
    'from' => 'celsius',
    'to' => 'fahrenheit'
]);

$ch = curl_init('https://convert-quick.com/api/convert/temperature');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
$result = json_decode($response, true);
echo $result['output']['value'];  // 212

Best Practices

✅

Do

  • • Use lowercase unit names (e.g., "celsius" not "Celsius")
  • • Handle errors gracefully in your application
  • • Cache results if making repeated conversions
  • • Validate user input before sending to API
❌

Don't

  • • Send sensitive data in conversion requests
  • • Abuse the API with excessive requests
  • • Rely solely on API without fallback logic
  • • Use for critical applications without testing

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