The Best Free Currency Exchange Rate API in 2026

If you need exchange rate data in your application, your options range from free-with-caveats to expensive-with-everything. Most developers start by searching "free currency API" and end up with a service that caps at 100 requests per month, requires a credit card for signup, or returns stale data cached from yesterday. Then they outgrow it, switch to a paid service, and rewrite their integration.

This article compares the major free currency exchange APIs available in 2026 and explains why AllRatesToday is the best option for most use cases: real-time mid-market rates for 160+ currencies, sourced from Reuters (Refinitiv) and interbank market feeds, with official SDKs and a generous free tier.

Comparing Free Currency APIs in 2026

Here is an honest comparison of what is available:

The key differentiators for AllRatesToday: real-time rates updated every 60 seconds (not daily), mid-market rates sourced from Reuters/Refinitiv, and official SDKs for three languages.

Getting Started in 30 Seconds

Sign up at allratestoday.com/register to get your free API key.

Fetch exchange rates

curl -X GET "https://allratestoday.com/api/v1/rates?source=USD&target=EUR" \
  -H "Authorization: Bearer YOUR_API_KEY"

Response:

{
  "source": "USD",
  "target": "EUR",
  "rate": 0.9234,
  "time": "2026-04-09T12:00:00Z"
}

Get multiple currency pairs

curl -X GET "https://allratestoday.com/api/v1/rates?source=USD" \
  -H "Authorization: Bearer YOUR_API_KEY"

Returns rates for all available target currencies against USD.

Historical rates

curl -X GET "https://allratestoday.com/api/historical-rates?source=USD&target=EUR&from=2026-01-01&to=2026-03-31" \
  -H "Authorization: Bearer YOUR_API_KEY"

Historical rates are useful for financial reporting, tax calculations, and charting exchange rate trends over time.

Official SDKs

Unlike most currency APIs that leave you writing raw HTTP calls, AllRatesToday provides official SDKs for the three most popular server-side languages.

JavaScript / TypeScript

npm install @allratestoday/sdk

import AllRatesToday from '@allratestoday/sdk';

const client = new AllRatesToday('YOUR_API_KEY');

// Get a single rate
const rate = await client.getRate('USD', 'EUR');
console.log(`1 USD = ${rate} EUR`);

// Convert an amount
const result = await client.convert('USD', 'EUR', 1000);
console.log(`$1,000 = €${result.result}`);

// Historical rates
const history = await client.getHistoricalRates('USD', 'EUR', '30d');
history.rates.forEach(point => {
  console.log(`${point.time}: ${point.rate}`);
});

Python

pip install allratestoday

from allratestoday import AllRatesToday

client = AllRatesToday("YOUR_API_KEY")

# Get exchange rate
rate = client.get_rate("USD", "EUR")
print(f"1 USD = {rate} EUR")

# Convert amount
result = client.convert("USD", "EUR", 1000)
print(f"$1,000 = €{result['result']}")

# Historical rates
history = client.get_historical_rates("USD", "EUR", "30d")
for point in history["rates"]:
    print(f"{point['time']}: {point['rate']}")

PHP

composer require allratestoday/sdk

use AllRatesToday\AllRatesToday;

$client = new AllRatesToday('YOUR_API_KEY');

// Get exchange rate
$rate = $client->getRate('USD', 'EUR');
echo "1 USD = {$rate[0]['rate']} EUR\n";

// Convert amount
$result = $client->convert('USD', 'EUR', 100);
echo "$100 = €{$result['result']}\n";

// Historical rates
$history = $client->getHistoricalRates('USD', 'EUR', '30d');
foreach ($history['rates'] as $point) {
    echo "{$point['time']}: {$point['rate']}\n";
}

React Price Display Component

A drop-in React component that shows prices in multiple currencies:

import { useState, useEffect } from 'react';
import AllRatesToday from '@allratestoday/sdk';

const client = new AllRatesToday('YOUR_API_KEY');

function useExchangeRate(from, to) {
  const [rate, setRate] = useState(null);

  useEffect(() => {
    client.getRate(from, to).then(setRate);
  }, [from, to]);

  return rate;
}

function PriceDisplay({ amount, from, to }) {
  const rate = useExchangeRate(from, to);

  if (!rate) return <span>Loading...</span>;

  return (
    <span>
      {(amount * rate).toFixed(2)} {to}
    </span>
  );
}

// Usage: <PriceDisplay amount={99.99} from="USD" to="EUR" />

Why AllRatesToday Over Other APIs?

• Real-time rates: Updated every 60 seconds from Reuters/Refinitiv and interbank feeds. Most free APIs only update once daily from the ECB.
• Mid-market rates: The true exchange rate between currencies, without any bank markup. This is the rate financial professionals reference.
• 160+ currencies: Major, minor, and exotic currency pairs. Far more than the 30 currencies offered by ECB-only services like Frankfurter.
• Official SDKs: Production-ready libraries for JavaScript, Python, PHP, and React. Install from npm, PyPI, or Packagist and start coding in minutes.
• Historical data: Access historical exchange rates for charting, reporting, and reconciliation.
• Easy signup: Get started quickly with the free tier. Upgrade only when you need to.
• Simple, consistent API: Clean JSON responses, standard REST conventions, Bearer token auth. No surprises.

Data Source and Accuracy

AllRatesToday sources its exchange rates from Reuters (Refinitiv) and interbank market feeds. These are mid-market rates — the real exchange rate between currencies before any bank markup is applied.

This is the same data used by financial institutions and platforms like Google Finance, XE, and Bloomberg for their rate displays. Unlike APIs that only provide ECB reference rates (published once daily at 16:00 CET for ~30 currencies), AllRatesToday delivers live rates updated every 60 seconds for 160+ currencies.

Pricing

AllRatesToday offers multiple plans from free to high-volume. For most applications — price displays, periodic rate fetching, financial dashboards — the free tier is enough to get started. View plans and pricing.

Quick Reference

• Get rates: GET /api/v1/rates?source=USD&target=EUR
• Historical: GET /api/historical-rates?source=USD&target=EUR&from=2026-01-01&to=2026-03-31
• Auth: Authorization: Bearer YOUR_API_KEY
• SDKs: npm install @allratestoday/sdk | npm install react-currency-localizer-realtime | pip install allratestoday | composer require allratestoday/sdk
• GitHub: allratestoday/exchange-rates-api