The 10 Best Free Currency APIs in 2026: Free Exchange Rate and Converter APIs, Ranked

Short answer: for most projects the best free currency API in 2026 is one that gives you real-time mid-market rates, a free tier you can test against, and no credit card at signup. This guide compares 10 of them — exchange rate APIs and currency converter APIs alike — on the numbers that matter: real free-tier limits, how often rates refresh, where the data comes from, and which ship official SDKs.

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 guide ranks the 10 best currency exchange APIs available to developers in 2026, compares their free tiers side by side, and explains why AllRatesToday is the best option for most use cases: real-time mid-market rates for 160+ currencies, sourced from institutional foreign exchange market data, with official SDKs and a free tier to start.

Just want a working key without the comparison shopping? Grab a free currency API key — Free tier, real-time rates, no credit card. For the full endpoint picture, including the keyless official-rate endpoint, see the exchange rate API overview.

Note: this guide covers live market rates. If you need the official rate a central bank published — for accounting, tax, or contracts — that is a different product with different winners: see our central bank exchange rate API ranking.

What Is a Currency Exchange API?

A currency exchange API is a web service that returns live or historical exchange rate data over HTTPS in a machine-readable format — usually JSON. Your application sends a request (e.g. "USD to EUR"), and the API responds with the current mid-market rate pulled from its data feeds. Instead of maintaining your own pipeline of bank feeds, FX aggregators, and exchange connections, you integrate one REST endpoint and let the provider handle the data plumbing.

Developers typically reach for a currency API to power:

• Localized pricing — display product prices in the visitor's local currency to reduce cart abandonment.
• Multi-currency billing — invoice SaaS customers in their own currency while reporting in a single base.
• Financial reporting — convert foreign transactions to the reporting currency at historical rates.
• Trading and analytics — feed dashboards, screeners, and backtests with live FX data.
• Cross-border payouts — calculate accurate settlement amounts for marketplaces and payroll systems.

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 institutional foreign exchange market data, and official SDKs for JavaScript, Python, PHP, Go and Rust.

The 10 Best Currency Exchange APIs in 2026, Ranked

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

Free Currency API Without an API Key

Some of the data behind AllRatesToday is open and needs no key, no signup and no quota. These endpoints are the quickest way to get a working rate into a script, a spreadsheet or a browser page. The ECB endpoints (/api/open/latest/{BASE} and /api/compat/) may be used commercially with a visible link to allratestoday.com; the central-bank tables are for non-commercial use without a key (see the terms):

• One URL, any base currency: GET https://allratestoday.com/api/open/latest/USD returns the ECB table re-based to USD (or any of its 30 currencies), with CORS open for browser code.
• Official ECB rates, keyless: GET https://allratestoday.com/api/open/central-bank/ecb returns the European Central Bank's latest reference table as JSON. Add ?format=csv for CSV. It is callable from the browser (CORS is open), so a front-end converter needs no backend.
• Any of 122 central banks and 4 tax authorities: swap ecb for a bank code such as fed, boe, rbi or boj. The full list is on the central bank rates API page.
• Frankfurter-compatible: GET https://allratestoday.com/api/compat/frankfurter/latest?from=USD&to=EUR answers in Frankfurter's shape, so existing code and libraries work unchanged.
• Visitor currency: GET https://allratestoday.com/api/open/geo returns the caller's country and local currency from their IP, for defaulting a price display.
• Bulk files: the full official-rate history is published daily as CSV and JSON on GitHub, Hugging Face and Kaggle (CC BY-NC 4.0 for the files).

curl "https://allratestoday.com/api/open/central-bank/ecb"
# {"bank":"ecb","rate_date":"2026-10-19","cadence":"daily",
#  "rates":[{"base":"EUR","quote":"USD","type":"reference","value":1.1225}, ...]}

What the keyless endpoints do not give you is real-time market rates: central banks publish once a day. For a live mid-market feed you need a key, and that is where the free tier and the exchange rate API start.

More detail: 7 free currency APIs without a key compared, open-source currency converter APIs you can self-host, and a free currency converter API for JavaScript with browser code.

How to Choose the Right API

• Real-time trading or pricing — pick a provider with 60-second updates (AllRatesToday, CurrencyFreaks Pro, XE).
• Accounting and reporting — historical endpoints and audit-grade sources matter more than latency. See how often exchange rates are updated.
• Crypto-first apps — CurrencyFreaks or CurrencyAPI for breadth; AllRatesToday if you need FX + metals.
• Prototypes and hobby projects — prefer free tiers without credit-card walls (AllRatesToday, ExchangeRate.host).
• Multi-asset dashboards — Alpha Vantage is the clear choice for equities + FX + crypto in one API.

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 (paid plans)

curl -X GET "https://allratestoday.com/api/v1/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.

Using It as a Currency Converter API

Fetching a rate and converting an amount are different jobs. Most APIs give you the rate and leave you to multiply — fine until you are doing it in three places and one of them rounds differently. A currency converter API does the arithmetic server-side and hands back the figure.

Add amount to the rates call and you get the conversion instead of the raw rate:

curl "https://allratestoday.com/api/v1/rates?source=USD&target=EUR&amount=1000" \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "from": { "currency": "USD", "amount": 1000 },
  "to":   { "currency": "EUR", "amount": 923.4 },
  "rate": 0.9234,
  "source": "mid-market"
}

Both the rate and the converted amount come back, so you can show the customer the figure and still display or audit the rate it came from. Leave amount off and the endpoint returns the plain rate exactly as before — the same key, the same endpoint, no separate integration.

For a converter widget you usually want one call per rate refresh rather than one per keystroke: fetch the rate once, convert locally as the user types, and re-fetch on an interval. That keeps a busy converter inside a small free tier.

Official SDKs

Unlike most currency APIs that leave you writing raw HTTP calls, AllRatesToday provides official SDKs for JavaScript, Python, PHP, Go and Rust, plus a React component and central-bank packages. The three most used are below; the SDK overview covers all of them with install commands and minimum versions.

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. The API key stays on your server: a small backend route fetches the rate and caches it for a minute, and the component calls that route.

// server.js (Express): holds the key, called by your frontend
app.get('/api/fx', async (req, res) => {
  const { from, to } = req.query;
  const r = await fetch(
    `https://allratestoday.com/api/v1/rates?source=${from}&target=${to}`,
    { headers: { Authorization: `Bearer ${process.env.ALLRATES_API_KEY}` } }
  );
  const [row] = await r.json(); // [{ rate, source, target, time }]
  res.set('Cache-Control', 'public, max-age=60').json({ rate: row.rate });
});

import { useState, useEffect } from 'react';

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

  useEffect(() => {
    // Calls your own backend route, never allratestoday.com with a key
    fetch(`/api/fx?from=${from}&to=${to}`)
      .then(r => r.json())
      .then(data => setRate(data.rate));
  }, [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 institutional foreign exchange market data. 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 in ECB-based feeds, and at live market prices rather than one daily fixing.
• 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 on any paid plan from €4.99/month.
• Easy signup: Test with no card. Upgrade when you go to production.
• Simple, consistent API: Clean JSON responses, standard REST conventions, Bearer token auth. No surprises.

Data Source and Accuracy

AllRatesToday sources its exchange rates from institutional foreign exchange market data. These are mid-market rates — the real exchange rate between currencies before any bank markup is applied.

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. The free plan is enough to evaluate the API for personal, non-commercial use. Production and commercial apps (price displays, periodic rate fetching, financial dashboards) start on the Small plan at €4.99/month for 5,000 requests. View plans and pricing.

Quick Reference

• Get rates: GET /api/v1/rates?source=USD&target=EUR
• Historical (paid plans): GET /api/v1/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: github.com/AllRates-Today (SDKs, MCP servers, open data)

FAQs

What is the best free currency exchange rate API?

It depends on what you need from the free tier. For ongoing free volume, Frankfurter (unlimited, daily ECB rates) and ExchangeRate-API (1,500 requests/month, daily updates) give the most. For real-time rates, AllRatesToday offers a free tier (no card) to evaluate real-time mid-market rates for 160+ currencies with official SDKs, then paid plans from €4.99/month.

How do I start with a free currency API?

Sign up for the provider's free plan, get an API key, and send a request to the latest-rates endpoint using curl or your language's HTTP client.

Can I get both real-time and historical rates?

Yes — quality APIs expose both. Historical endpoints usually accept a YYYY-MM-DD date parameter. See how to handle base currency conversion for working with historical data across bases.

Is there a free currency converter API?

Yes. AllRatesToday converts server-side: pass amount alongside source and target and the response carries both the converted figure and the rate used. It is the same endpoint and the same free tier as a plain rate lookup, so a converter needs no separate integration.

Is there a free currency API without an API key?

Yes, for official rates. AllRatesToday's open endpoints return the latest table from any of 122 central banks keyless, for example https://allratestoday.com/api/open/central-bank/ecb, and Frankfurter is keyless for ECB rates. Real-time market rates need a free key because the feed is metered.

How many currencies does AllRatesToday support?

Over 160, with real-time mid-market rates refreshed every 60 seconds.

Does AllRatesToday require a credit card?

No. The free plan needs only an email address, no card. Paid plans start at €4.99/month.

Does AllRatesToday have official SDKs?

Yes. JavaScript/TypeScript, Python, PHP, Go and Rust, plus a React component and an MCP server for AI agents.

Do free tiers support cryptocurrency?

Some do (CurrencyFreaks, CurrencyAPI). Always check the documentation for supported symbols before committing.

How often are rates updated?

Free tiers typically refresh daily or hourly. Paid tiers drop to 60 seconds or faster. AllRatesToday updates every 60 seconds — full details in how often are exchange rates updated.