Developer API

Integrate powerful conversion tools into your applications with our free API.

⚡ Quick Start

Get started in 60 seconds with your free API key - simple registration, unlimited requests.

Bash / cURL
# Currency Conversion Example
curl -X POST https://www.konvertibly.com/api/currency/convert \
  -H "Content-Type: application/json" \
  -d '{
    "fromCurrency": "USD",
    "toCurrency": "EUR",
    "amount": 100
  }'
JavaScript / Fetch
// Currency Conversion Example
const response = await fetch('https://www.konvertibly.com/api/currency/convert', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    fromCurrency: 'USD',
    toCurrency: 'EUR',
    amount: 100
  })
});

const data = await response.json();
console.log(data.data.result); // Converted amount
Python / Requests
# Currency Conversion Example
import requests

url = "https://www.konvertibly.com/api/currency/convert"
payload = {
    "fromCurrency": "USD",
    "toCurrency": "EUR",
    "amount": 100
}

response = requests.post(url, json=payload)
data = response.json()
print(data['data']['result'])  # Converted amount
PHP / cURL
// Currency Conversion Example
$url = "https://www.konvertibly.com/api/currency/convert";
$data = json_encode([
    "fromCurrency" => "USD",
    "toCurrency" => "EUR",
    "amount" => 100
]);

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type:application/json']);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$result = curl_exec($ch);
$data = json_decode($result, true);
echo $data['data']['result'];  // Converted amount

✨ Why Choose Konvertibly API?

🔓

Free API Key

Register once, use forever - completely free with unlimited requests.

💸

Forever Free

Unlimited requests, zero cost. Build amazing apps without worrying about bills.

Lightning Fast

Sub-100ms response times with global CDN and Redis caching.

📊

Live Data

Real-time exchange rates, updated every 60 seconds from trusted sources.

🌍

Global Coverage

210+ currencies, 50+ countries, infinite conversion possibilities.

📱

Developer-Friendly

Clean JSON responses, comprehensive docs, code examples in 4+ languages.

📡 API Endpoints

All endpoints return JSON responses with consistent formatting.

💱

Currency API

  • POST /api/currency/convert

    Convert between 210+ currencies with live rates

  • GET /api/currency/currencies

    Get list of all supported currencies

  • GET /api/currency/historical

    Get historical exchange rate data

  • GET /api/currency/compare

    Compare multiple currencies side-by-side

📍

Location API

  • GET /api/location

    Auto-detect user location and currency from IP

  • GET /api/location/currency/:code

    Get currency for specific country code

🎓

Education API

  • POST /api/education/calculate-gpa

    Calculate GPA from grades

  • POST /api/education/convert-gpa

    Convert GPA between scales (4.0, 5.0, 10.0)

  • POST /api/education/reading-time

    Calculate reading time for text

  • GET /api/education/tools

    Get all education conversion tools

🌤️

Weather API

  • GET /api/weather/convert

    Convert weather measurements

  • GET /api/weather/heat-index

    Calculate heat index

  • GET /api/weather/wind-chill

    Calculate wind chill factor

  • GET /api/weather/uv-index

    Get UV index information

👕

Clothing API

  • GET /api/clothing/convert

    Convert clothing sizes (US, UK, EU)

  • GET /api/clothing/size-chart

    Get complete size chart

  • GET /api/clothing/systems

    Get all sizing systems

📁

File Upload API

  • POST /api/files/upload

    Upload files (max 10 files, 50MB each)

  • GET /api/files/list

    List uploaded files

  • DELETE /api/files/:fileId

    Delete uploaded file

🔐 Authentication

No authentication required! All Konvertibly APIs are completely open and free to use. Simply make HTTP requests and receive JSON responses. No API keys, no OAuth, no complexity.

We believe in keeping things simple. Focus on building great products, not managing authentication flows.

⏱️ Rate Limits

We implement fair usage rate limits to ensure service quality for all users.

Tier Requests per Minute Requests per Day Cost
Free (No API Key) 60 requests/min 10,000 requests/day $0
Fair Usage Unlimited Unlimited $0

Note: We don't enforce strict rate limits. As long as you're not abusing the service (e.g., DDoS attacks), you're free to make as many requests as you need. Be reasonable, and we'll keep it free forever.

📋 Response Format

All API responses follow a consistent JSON structure:

✅ Success Response

{
  "success": true,
  "data": {
    "from": "USD",
    "to": "EUR",
    "amount": 100,
    "result": 92.35,
    "rate": 0.9235,
    "timestamp": "2025-12-07T10:30:00Z",
    "source": "exchangerate-api.com"
  }
}

❌ Error Response

{
  "success": false,
  "error": {
    "message": "Missing required parameters: fromCurrency and toCurrency"
  }
}

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