Exchange Rate API vs ExchangeRate-API: Which Currency API Should You Choose?

ExchangeRate-API and Exchange Rate API have similar-sounding names, serve similar use cases, and both appear in search results when you look for a currency exchange rate API. That overlap causes real confusion. This article is a direct, side-by-side comparison.

Side-by-Side Comparison

Data Sources

ExchangeRate-API describes its data sources as "various financial sources" without naming specific providers. Rates are published once per day.

Exchange Rate API sources its rates from Reuters (Refinitiv) and interbank market feeds. These are mid-market rates: the true exchange rate between two currencies before any bank markup is applied.

Update Frequency

ExchangeRate-API updates its rates once per day.

Exchange Rate API updates rates every 60 seconds. If you are building a trading dashboard, a checkout flow, or any system where rate accuracy within the last minute matters, this is a meaningful difference.

Official SDKs

ExchangeRate-API: No Official SDKs

// ExchangeRate-API - raw fetch (no official SDK)
const response = await fetch(
  'https://v6.exchangerate-api.com/v6/YOUR_API_KEY/latest/USD'
);
const data = await response.json();
const eurRate = data.conversion_rates.EUR;

Exchange Rate API: Official SDKs for Four Platforms

JavaScript / TypeScript

npm install @exchangerateapi/sdk

import ExchangeRateAPI from '@exchangerateapi/sdk';

const client = new ExchangeRateAPI('erapik_...');

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

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

Python

pip install exchangerateapi

from exchangerateapi import ExchangeRateAPI

client = ExchangeRateAPI("erapik_...")

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

PHP

composer require exchangerateapi/sdk

use ExchangeRateAPI\ExchangeRateAPI;

$client = new ExchangeRateAPI('erapik_...');
$rate = $client->getRate('USD', 'EUR');
echo "1 USD = {$rate[0]['rate']} EUR\n";

API Design Comparison

ExchangeRate-API embeds the API key directly in the URL path. This approach is simple but API keys can leak into browser history, server logs, and referrer headers.

Exchange Rate API uses standard Bearer token authentication in the Authorization header, which follows REST conventions and keeps credentials out of URLs.

When to Choose ExchangeRate-API

• Daily rates are sufficient for your use case
• You prefer URL-based auth for quick prototypes
• You are already integrated and daily updates meet your needs

When to Choose Exchange Rate API

• You need real-time rates (updated every 60 seconds)
• Data source transparency matters (Reuters/Refinitiv)
• You want official SDKs (JS/TS, Python, PHP, React)
• You need mid-market rates for invoicing, accounting, or compliance
• You want historical data on a free plan

Migration Guide: ExchangeRate-API to Exchange Rate API

Step 1: Get your API key

Sign up at exchange-rateapi.com/register.

Step 2: Replace raw HTTP calls with the SDK

Before (ExchangeRate-API):

const response = await fetch(
  'https://v6.exchangerate-api.com/v6/YOUR_KEY/pair/USD/EUR/1000'
);
const data = await response.json();
console.log(data.conversion_result);

After (Exchange Rate API SDK):

import ExchangeRateAPI from '@exchangerateapi/sdk';

const client = new ExchangeRateAPI('erapik_...');
const result = await client.convert('USD', 'EUR', 1000);
console.log(result.result);

Summary

ExchangeRate-API is a solid, simple API for applications that only need daily exchange rates.

Exchange Rate API is the better choice for production applications that need real-time rates (updated every 60 seconds), transparent data sourcing from Reuters/Refinitiv, mid-market rates, and official SDKs.

npm install @exchangerateapi/sdk