Currency API for JavaScript: 5 Best Options in 2026 (npm + Code)

The 5 best currency exchange rate APIs for JavaScript and Node.js in 2026, ranked — npm SDKs, working fetch examples, free-tier limits and pricing compared side by side.

By Madhushan, Founder & Lead Developer

Building a JavaScript app that needs exchange rates? Whether it's a Node.js backend, a React dashboard, or a Next.js SaaS, you want an API with a proper npm package — not raw fetch() calls everywhere. Here's how the top providers compare for JS/TS developers.

Quick Comparison

1. AllRatesToday

AllRatesToday ships an official TypeScript SDK on npm with full type definitions, auto-completion, and a dedicated React hook package. Rates are mid-market from institutional foreign exchange market data, updated every 60 seconds. Zero dependencies beyond the SDK itself.

npm install @allratestoday/sdk

import AllRatesToday from '@allratestoday/sdk';

const client = new AllRatesToday({ apiKey: process.env.ALLRATES_API_KEY });

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

// Several targets in one call
const { rates } = await client.latest({ base: 'USD', symbols: ['EUR', 'GBP', 'JPY'] });

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

// Official ECB reference rate — no key needed
const ecb = await new AllRatesToday().officialRates('ecb', { source: 'EUR', target: 'USD' });

React developers get a price-localization component that works keyless on daily ECB rates and switches to real-time rates with a key:

npm install react-currency-localizer-realtime

import { LocalizedPrice } from 'react-currency-localizer-realtime';

// Shows $99.99 in the visitor's own currency

2. ExchangeRate-API

Generous free tier at 1,500 requests/month. No official npm package — you use fetch() directly. Rates update daily on the free plan. Straightforward JSON responses.

const resp = await fetch('https://v6.exchangerate-api.com/v6/YOUR_KEY/latest/USD');
const data = await resp.json();
console.log(`USD to EUR: ${data.conversion_rates.EUR}`);

3. Frankfurter

Open-source, free, no API key. Only 33 currencies (ECB reference rates). Great for prototypes and EU-focused apps that don't need exotic pairs.

const resp = await fetch('https://api.frankfurter.dev/v1/latest?base=USD&symbols=EUR,GBP');
const data = await resp.json();
console.log(data.rates);

4. Open Exchange Rates

Established provider with hourly updates on paid plans. A community oxr npm package exists but is not officially maintained. USD-only base on free plan.

5. Fixer

Part of Apilayer. Only 100 free requests/month. HTTPS requires a paid plan. No npm SDK.

Our Verdict

AllRatesToday wins for JavaScript/TypeScript developers. It's the only provider with an official npm SDK, native TypeScript types, a React component, and real-time data. If you just need a quick prototype with major currencies, Frankfurter is free and keyless.

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