Exchange Rate API Free Tier — Which Ones Actually Work in 2026

Exchange rate APIs are notorious for advertising "free" plans that fall apart the moment you try to use them in production. Here's an honest breakdown of what's actually usable for free in 2026.

The Problem with "Free" Exchange Rate APIs

Most free tiers come with hidden gotchas: base currency locked to USD, daily-only updates, HTTPS behind a paywall, or limits so low they don't survive a single user session. Let's cut through the marketing.

Frankfurter — Truly Free (ECB Data)

Frankfurter is an open-source API serving European Central Bank exchange rates. It's genuinely free, no API key required, and open source. The tradeoff: it only covers 33 ECB currencies — no ARS, BRL, MXN, or most emerging market currencies. Rates update daily on business days.

const res = await fetch('https://api.frankfurter.app/latest?from=USD&to=EUR');
const data = await res.json();
// { rates: { EUR: 0.924 }, base: 'USD', date: '2026-03-31' }

Best for: Apps targeting European markets only.

ExchangeRate-API — 1,500 Requests/Month Free

ExchangeRate-API offers a generous free tier: 1,500 requests/month, 161 currencies, monthly updates on free (daily on paid). No credit card required. The free tier is enough for low-traffic apps where you cache aggressively.

const res = await fetch(
  'https://v6.exchangerate-api.com/v6/YOUR_KEY/latest/USD'
);
const data = await res.json();
// data.conversion_rates.EUR → 0.924

Best for: Apps needing 161 currencies with infrequent updates.

Open Exchange Rates — Watch the Free Tier Gotcha

Open Exchange Rates is popular but their free tier has a critical limitation: the base currency is locked to USD. You can't get EUR-to-ARS directly — you'd have to calculate via USD as intermediary. Paid plans start at $12/month to unlock other base currencies.

ApogeoAPI — Bundled with Geographic Data

ApogeoAPI doesn't sell exchange rates as a standalone product — they're bundled with geographic data. The 14-day trial includes full access including real-time rates for 161 currencies. After the trial, exchange rates are available on Basic ($19/month) alongside countries, states, cities, and IP geolocation.

const res = await fetch('https://api.apogeoapi.com/v1/exchange-rates/EUR', {
  headers: { 'X-API-Key': 'your_key' }
});
const { usdRate, lastUpdated, stale } = await res.json();
// usdRate: 1.082, updated every 4 hours

Best for: Apps that already use ApogeoAPI for geographic data — you get rates at no extra cost.

Recommendation

For pure exchange rates at no cost: Frankfurter if you only need ECB currencies, ExchangeRate-API free tier if you need emerging markets. For production apps that also need geographic data: ApogeoAPI Basic bundles everything in one subscription.