# Using Currency Converter and Currency Exchange API

Global transactions are the norm, businesses and developers need reliable ways to convert currencies accurately and instantly. Whether it’s an eCommerce store with international customers or a finance app calculating currency values, a [**currency converter API**](https://fixer.io/documentation) and a currency exchange API offer the tools needed to automate and streamline the process.

This guide explores how these APIs work, their use cases, and how Fixer.io provides a dependable solution.

**What Is a Currency Converter API?**

A currency converter API allows developers to convert amounts from one currency to another using real-time or historical exchange rates. It acts as a backend service that returns precise conversion results based on current market rates.

#### **Common Features:**

* Real-time conversion between any two currencies
    
* JSON-based output for easy integration
    
* Support for a wide range of currencies
    
* Lightweight and fast responses for web or mobile apps  
    

This API is especially useful for applications that require user-input conversions like finance calculators, travel apps, or invoicing platforms.

**What Is a Currency Exchange API?**

A currency exchange API provides access to the actual exchange rates between global currencies. It doesn’t perform the conversion for you, but it gives you the raw data needed to compute it.

#### **What It Offers:**

* Exchange rates for over 170 currencies
    
* Historical rate data
    
* Base currency selection and filtering
    
* High-frequency updates depending on the plan  
      
    

Together with a converter API, this tool forms the backbone of multi-currency financial apps.

**Why Use Both APIs?**

For most practical applications, developers need both:

* **Currency exchange API** for getting up-to-date rates
    
* **Currency converter API** for applying those rates to calculations  
      
    

For example, an invoicing tool can pull the latest exchange rate using the exchange API and then convert the invoice total using the converter API, ensuring the user always sees the correct amount.

**How Fixer.io Supports Both APIs**

[Fixer.io](https://fixer.io/) provides both currency exchange API and currency converter API functionalities through a unified platform. With one simple REST API, you can fetch exchange rates and perform conversions seamlessly.

#### **Highlights:**

* Trusted by developers and businesses worldwide
    
* Updated every 60 seconds (premium plans)
    
* Secure HTTPS support
    
* Flexible pricing for all business sizes
    
* Developer-friendly documentation  
      
    

You can access real-time and historical data, convert currencies, and ensure reliable performance across your application.

**Developer Integration Guide**

Here’s a sample API call to get conversion results using Fixer.io:

http

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https://data.fixer.io/api/convert?access\_key=YOUR\_API\_KEY&from=USD&to=EUR&amount=100  

This request will return the converted amount from USD to EUR for a given amount, using the latest exchange rate available.

Fixer also provides endpoints for:

* **Latest exchange rates**
    
* **Historical data by date**
    
* **Time-series data**
    
* **Fluctuation tracking  
      
    **
    

**Business Use Case: Invoicing Platform**

Let’s say a small business offers services to clients in multiple countries. They need to:

* Convert the invoice amount to the client’s currency
    
* Apply current exchange rates
    
* Display both currencies for clarity  
      
    

By integrating the currency exchange API and currency converter API, they can:

* Automate the process
    
* Ensure transparency
    
* Avoid manual calculation errors  
    

This not only builds trust with clients but also saves time for the business.

**Use Case: Mobile Travel App**

A travel app showing expenses in local currency can use these APIs to:

1. Pull live exchange rates when the user enters a new country.
    
2. Convert their home currency budget into the destination currency.
    
3. Update all displayed prices based on real-time data.  
    

With just a few lines of code, the app delivers a highly personalized and accurate travel experience.

**Fixer.io Plans for All Needs**

Fixer.io offers flexible plans:

* **Free Tier**: Great for startups or personal projects
    
* **Basic/Premium Plans**: Support SSL, more API calls, faster updates, and extended historical data  
    

Small businesses can start with the free tier and move to premium as their usage grows.

**Historical and Time-Series Data**

For applications that require more than just the current rate, Fixer.io provides:

* **Historical exchange rates**
    
* **Time-series trends**
    
* **Currency fluctuation tracking  
    **
    

This is ideal for:

* Budgeting and financial forecasting tools
    
* Reports and analytics dashboards
    
* Investment and trading platforms
    

Example historical API call:

http

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https://data.fixer.io/api/2024-05-01?access\_key=YOUR\_API\_KEY&base=USD&symbols=INR  

Whether you're building a multi-currency checkout, a travel expense tracker, or a financial dashboard, using a currency converter API along with a [**currency exchange API**](https://fixer.io/) helps ensure accuracy, automation, and a better user experience.

Fixer.io delivers a reliable, developer-friendly solution that empowers apps with up-to-date currency data and fast, accurate conversions. It’s trusted by startups, enterprises, and independent developers alike.