--- title: "20 Currency & Exchange Rate API Questions Answered (2026)" description: "Straight answers to the 20 most-asked questions developers have about currency APIs, exchange rate APIs, forex APIs, free vs paid providers, Xe, Frankfurter, ExchangeRate-API, Fixer, and more." canonical: https://allratestoday.com/blog/20-currency-exchange-rate-api-questions-answered/ source: AllRatesToday (https://allratestoday.com/) — Markdown mirror of the page above; index of all pages at https://allratestoday.com/llms.txt generated: 2026-10-17T09:36:33.201Z --- ![Developer FAQ and questions](https://images.pexels.com/photos/221164/pexels-photo-221164.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940) Developers keep searching for the same set of questions about currency APIs, exchange rate APIs, and forex APIs: which ones are free, which are reliable, what Xe costs, whether Google has an API, how to build a converter in Python. We pulled the 20 most-asked from Google's People Also Ask and answered each one directly — no fluff, no affiliate padding. ## Q1.Is there a free API for currency conversion? **Yes — several.** The main free options in 2026: - [Frankfurter](https://api.frankfurter.dev/) — 100% free, no API key, ECB daily reference rates for ~30 currencies, historical back to 1999. - [fawazahmed0/currency-api](https://github.com/fawazahmed0/currency-api) — free via jsDelivr CDN, 200+ currencies including crypto. - [ExchangeRate-API](https://www.exchangerate-api.com/) — 1,500 requests/month on the free tier (key required). - [freecurrencyapi.com](https://freecurrencyapi.com/) — 5,000 requests/month. - [AllRatesToday](https://allratestoday.com/) — 300 free requests (one-time, no card) for testing and personal projects, rates updated every 60 seconds; paid plans from €4.99/month for production and commercial use. For deeper coverage of the trade-offs, see [our developer guide on free currency APIs](https://allratestoday.com/blog/is-there-a-free-api-for-currency-conversion/). ## Q2.What is a currency API? A currency API is a REST web service that returns exchange rates between currencies, usually as JSON. A typical call: ``` GET https://allratestoday.com/api/v1/rates?source=USD&target=EUR → [{"rate": 0.85, "source": "USD", "target": "EUR", "time": "2026-04-19T12:00:00Z"}] ``` Currency APIs power e-commerce checkout, finance dashboards, accounting tools, travel apps, international payroll, and any software that displays money in more than one currency. Full background in [What is a currency API?](https://allratestoday.com/blog/what-is-a-currency-api/). ## Q3.What is a forex API? A **forex (FX) API** is a currency API built for trading rather than display. Expect: - Tick-level **bid/ask quotes** with millisecond latency (not just a mid-market rate) - Historical OHLC (open/high/low/close) data for charting - Sometimes **order execution** endpoints — place, modify, cancel Examples: OANDA, MetaTrader (MT4/MT5), TraderMade, Polygon.io, FXCM. General-purpose currency APIs only return reference mid-market rates and are not suitable for trading. ## Q4.What is an FX API? "FX API" is another name for "forex API." Some enterprise providers — banks, Stripe's FX product, Bloomberg, OCBC — reserve "FX API" for streaming quotes and execution services covering 100+ pairs. In casual developer conversation, "currency API" and "FX API" are often used interchangeably. ## Q5.What is an open exchange rate? Two meanings: 1. **Generic:** an exchange rate openly accessible through a public API — no private contract needed. 2. **Specific:** [Open Exchange Rates](https://openexchangerates.org/) is the name of a commercial provider publishing rates for 200+ currencies since 2011. Free tier: 1,000 requests/month, hourly updates, USD base only. ## Q6.Is the Frankfurter API free? Yes. [Frankfurter](https://www.frankfurter.dev/) is a free, open-source currency data API with no key, no signup, and no documented rate limit for normal use. It tracks ~30 currencies using European Central Bank daily reference rates and supports historical data back to 1999. Because it's ECB-based, rates update once per business day around 16:00 CET — great for accounting and display, not for trading. ## Q7.Is an exchange rate API free? Depends on the provider: | Provider | Free tier | Key? | | --- | --- | --- | | Frankfurter | Unlimited | No | | fawazahmed0 | Unlimited | No | | [AllRatesToday](https://allratestoday.com/) | 300 requests (one-time) | Yes | | [Exchange Rate API](https://exchange-rateapi.com/) (now AllRatesToday) | Same 300 one-time requests | Yes | | ExchangeRate-API | 1,500/mo | Yes | | freecurrencyapi.com | 5,000/mo | Yes | | Open Exchange Rates | 1,000/mo | Yes | | Fixer.io | 100/mo | Yes | | Xe / OANDA / Bloomberg | None | Yes | See [Best free currency exchange API (2026)](https://allratestoday.com/blog/best-free-currency-exchange-api-2026/) for a detailed comparison. ## Q8.Is ExchangeRate-API free? ExchangeRate-API has a free plan of **1,500 requests/month**, no credit card required. Fine for hobby projects, prototypes, and small internal tools. The terms of service explicitly ask commercial users to upgrade — so it's not positioned for production traffic. ## Q9.How much does ExchangeRate-API cost? Paid plans as of 2026: - **Pro** — $13.99/month, 30,000 requests/month, hourly updates - **Business** — $29/month, 100,000 requests/month - **Volume** — $49/month, 1.5M requests/month, minute-level updates - **Enterprise** — custom Prices change occasionally; check [their pricing page](https://www.exchangerate-api.com/) for current numbers. ## Q10.Does Xe have an API? Yes. [Xe Currency Data API](https://www.xe.com/platform/xecurrencydata/) provides real-time and historical exchange rates for 170+ currencies. It's used by Fortune 500 companies, banks, and fintechs, with optional SLAs and uptime guarantees. Full breakdown in [Does Xe have an API?](https://allratestoday.com/blog/does-xe-have-an-api/). ## Q11.Is the Xe API free? No. Xe has no public free tier. Pricing is enterprise-only and typically starts around **$799/month** depending on volume and features. For free access, Frankfurter, ExchangeRate-API's free tier, or [AllRatesToday](https://allratestoday.com/)'s free plan are the common alternatives. ## Q12.Is the Google Currency Converter API free? There is no official public Google Currency API (the old Google Finance API was retired in 2012). What exists: - The `GOOGLEFINANCE` function in Google Sheets — free, ~20-minute delay, not a REST API. - Unofficial wrappers (e.g. `currency-api.appspot.com`) — community-hosted, no SLA, can disappear without warning. Don't depend on Google for production currency rates. Use a supported provider. ## Q13.Is Fixer.io reliable? Yes, within its bounds. Fixer.io is owned by **apilayer** and has been running since 2015. Paid plans have uptime guarantees and are generally reliable. Limitations on the free tier are heavy: 100 requests/month, HTTP only (no HTTPS), and EUR is the only allowed base currency. Most production users end up on Basic ($14.99/month) or Professional ($59.99/month). Our side-by-side comparison: [AllRatesToday vs Fixer, Xe, ExchangeRate-API](https://allratestoday.com/blog/allratestoday-vs-fixer-xe-exchangerate-api/). ## Q14.Is the MT5 API free? No. MetaTrader 5 Manager and Gateway APIs require a licensed MT5 server and a paid integration agreement with MetaQuotes. Brokers may offer trial access to demo accounts. If you only need exchange rates (not trade execution), a plain currency API is dramatically simpler and cheaper. ## Q15.How do you make a currency converter in Python with an API? Minimal working example using Frankfurter (no key needed): ``` import requests def convert(amount, src, dst): r = requests.get("https://api.frankfurter.dev/v1/latest", params={"from": src, "to": dst}) r.raise_for_status() rate = r.json()["rates"][dst] return amount * rate, rate amount, rate = convert(100, "USD", "EUR") print(f"100 USD = {amount:.2f} EUR (rate {rate})") ``` Add error handling for timeouts and unknown currency codes, cache results for 30–60 minutes, and you have a production-ready converter. Deeper walk-through in [How to get live exchange rates in Python](https://allratestoday.com/blog/how-to-get-live-exchange-rates-python/). ## Q16.What is the formula to calculate an exchange rate? The exchange rate is the ratio of two currency amounts: ``` rate = target_amount / source_amount ``` If 100 USD buys 85 EUR, the USD→EUR rate is `85 / 100 = 0.85`. To convert any amount, multiply by the rate: ``` 250 USD × 0.85 = 212.50 EUR ``` The inverse (EUR→USD) is `1 / 0.85 ≈ 1.176`. Real-world rates include a spread — the "buy" and "sell" rates differ slightly, and that gap is the provider's margin. More: [Mid-market vs retail exchange rates](https://allratestoday.com/blog/mid-market-vs-retail-exchange-rates/). ## Q17.What is the GOOGLEFINANCE function for exchange rates? In Google Sheets: ``` =GOOGLEFINANCE("CURRENCY:USDEUR") ``` Replace `USDEUR` with any two concatenated ISO 4217 codes (`GBPJPY`, `AUDCAD`, etc.). For historical rates, add a date: ``` =GOOGLEFINANCE("CURRENCY:USDEUR", "price", DATE(2024,1,1)) ``` Rates are delayed ~20 minutes. Fine for spreadsheets; don't build production systems on it. For Excel, see [How to get exchange rates in Excel](https://allratestoday.com/blog/excel-exchange-rates/). ## Q18.Which is the best currency converter? Depends on the use case: - **Sending money abroad:** [Wise](https://wise.com/) — real mid-market rate, transparent fees. - **Quick lookup on web/mobile:** Google search or [XE.com](https://xe.com/). - **Embedding in software:** [AllRatesToday](https://allratestoday.com/) or Frankfurter. - **Enterprise / trading:** Xe, OANDA, or Bloomberg. For developers comparing providers head-to-head, see [10 best currency exchange APIs (2026)](https://allratestoday.com/blog/best-free-currency-exchange-api-2026/). ## Q19.What is the best currency converter app to use? Most-recommended consumer apps in 2026: - **Wise** — best mid-market rate + actual money transfer. - **XE Currency** — clean UI, offline mode for travel. - **Revolut** — multi-currency account with in-app conversion. - **Currency Converter Plus** — simple free converter (ad-supported). ## Q20.Where should you convert currency for the best exchange rate? You get closest to the mid-market rate with online-first providers: **Wise**, **Revolut**, **Currencies Direct**, or **OFX**. Traditional banks and airport kiosks mark up the rate by 2–5% on top of a fee. Travel-friendly credit cards (no foreign transaction fee) are good for purchases abroad; avoid "Dynamic Currency Conversion" at the point of sale — always pay in the local currency. Rule of thumb: check the mid-market rate first (Google, AllRatesToday, XE), then compare the rate you're offered. Any gap is the provider's margin. ## Need a reliable currency API for your app? AllRatesToday gives you real-time rates for 160+ currencies, with historical data on paid plans from €4.99/month. Start with 300 free requests, no credit card required. [Get your free API key](https://allratestoday.com/register) Get started ``` npm install @allratestoday/sdk ```