Build A Currency Converter App in HTML CSS & JavaScript

Hey there, today in this blog, you’ll learn how to Build A Currency Converter App in HTML CSS & JavaScript. In the earlier blog, I have shared Create Animated Minions Using HTML & CSS and now it’s time to create a currency converter using pure JavaScript.

In this app (Currency Converter in JavaScript), you can enter your amount and convert your currency to a different country’s currency. You can’t leave the amount field blank or enter 0 as an amount. If you do it, then “1” will be filled automatically in the amount field.

You can also easily exchange or reverse the two countries’ currency by clicking on the exchange icon. This is best project for JavaScript Intermediater.

Codes & Logic Behind JavaScript Currency Converter App

In the JavaScript file (country-list.js), I stored all possible country code and their currency code as an object. Then in the script.js file, first, I created an options tag and added those currency codes inside each option tag using for-in loop and inserted these tags inside the select tag.

After this, I created a function and got the user-entered amount. Then I sent a get request to an exchange rate API by passing the user selected “from” currency code. API returned an object of the all-country currency conversion rate of the user-selected “from” currency.

Firstly, I got the user selected “to” currency conversion rate, and then I calculate it with the user-entered amount and show it in the exchange rate text. Once it’s done, for swapping the currency codes, I just reversed the “from” currency to “to” currency and then call the function. For flags, I used API to show the user-selected country flag

Currency Converter App in JavaScript

To create this project (Currency Converter in JavaScript). First, you need to create four Files: HTML, CSS & JavaScript Files. After creating these files just paste the following codes into your file.


First, create an HTML file with the name of index.html and copy paste the given codes in your HTML file. Remember, you’ve to create a file with .html extension.

<!DOCTYPE html>
<!-- Coding By Codegyan - -->
<html lang="en" dir="ltr">
    <meta charset="utf-8">
    <title>Currency Converter App in JavaScript | Codegyan</title>
    <link rel="stylesheet" href="style.css">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- FontAweome CDN Link for Icons -->
    <link rel="stylesheet" href=""/>
    <div class="wrapper">
      <header>Currency Converter</header>
      <form action="#">
        <div class="amount">
          <p>Enter Amount</p>
          <input type="text" value="1">
        <div class="drop-list">
          <div class="from">
            <div class="select-box">
              <img src="" alt="flag">
              <select> <!-- Options tag are inserted from JavaScript --> </select>
          <div class="icon"><i class="fas fa-exchange-alt"></i></div>
          <div class="to">
            <div class="select-box">
              <img src="" alt="flag">
              <select> <!-- Options tag are inserted from JavaScript --> </select>
        <div class="exchange-rate">Getting exchange rate...</div>
        <button>Get Exchange Rate</button>
    <!--- JavaScript  ----->
    <script src="js/country-list.js"></script>
    <script src="js/script.js"></script>



Second, create a CSS file with the name of style.css and paste the given codes in your CSS file. Remember, you’ve to create a file with .css extension.

/* Import Google Font - Poppins */
@import url(';500;600;700&display=swap');
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 0 10px;
  background: #675AFE;
  color: #fff;
  background: #675AFE;
  width: 370px;
  padding: 30px;
  border-radius: 7px;
  background: #fff;
  box-shadow: 7px 7px 20px rgba(0, 0, 0, 0.05);
.wrapper header{
  font-size: 28px;
  font-weight: 500;
  text-align: center;
.wrapper form{
  margin: 40px 0 20px 0;
form :where(input, select, button){
  width: 100%;
  outline: none;
  border-radius: 5px;
  border: none;
form p{
  font-size: 18px;
  margin-bottom: 5px;
form input{
  height: 50px;
  font-size: 17px;
  padding: 0 15px;
  border: 1px solid #999;
form input:focus{
  padding: 0 14px;
  border: 2px solid #675AFE;
form .drop-list{
  display: flex;
  margin-top: 20px;
  align-items: center;
  justify-content: space-between;
.drop-list .select-box{
  display: flex;
  width: 115px;
  height: 45px;
  align-items: center;
  border-radius: 5px;
  justify-content: center;
  border: 1px solid #999;
.select-box img{
  max-width: 21px;
.select-box select{
  width: auto;
  font-size: 16px;
  background: none;
  margin: 0 -5px 0 5px;
.select-box select::-webkit-scrollbar{
  width: 8px;
.select-box select::-webkit-scrollbar-track{
  background: #fff;
.select-box select::-webkit-scrollbar-thumb{
  background: #888;
  border-radius: 8px;
  border-right: 2px solid #ffffff;
.drop-list .icon{
  cursor: pointer;
  margin-top: 30px;
  font-size: 22px;
form .exchange-rate{
  font-size: 17px;
  margin: 20px 0 30px;
form button{
  height: 52px;
  color: #fff;
  font-size: 17px;
  cursor: pointer;
  background: #675AFE;
  transition: 0.3s ease;
form button:hover{
  background: #4534fe;

Third, create a JavaScript file with the name of country-list.js and paste the given codes in your JavaScript file. Remember, you’ve to create a file with .js extension. In this file, we’ll store all country code and their currency code.

let country_list = {
    "AED" : "AE",
    "AFN" : "AF",
    "XCD" : "AG",
    "ALL" : "AL",
    "AMD" : "AM",
    "ANG" : "AN",
    "AOA" : "AO",
    "AQD" : "AQ",
    "ARS" : "AR",
    "AUD" : "AU",
    "AZN" : "AZ",
    "BAM" : "BA",
    "BBD" : "BB",
    "BDT" : "BD",
    "XOF" : "BE",
    "BGN" : "BG",
    "BHD" : "BH",
    "BIF" : "BI",
    "BMD" : "BM",
    "BND" : "BN",
    "BOB" : "BO",
    "BRL" : "BR",
    "BSD" : "BS",
    "NOK" : "BV",
    "BWP" : "BW",
    "BYR" : "BY",
    "BZD" : "BZ",
    "CAD" : "CA",
    "CDF" : "CD",
    "XAF" : "CF",
    "CHF" : "CH",
    "CLP" : "CL",
    "CNY" : "CN",
    "COP" : "CO",
    "CRC" : "CR",
    "CUP" : "CU",
    "CVE" : "CV",
    "CYP" : "CY",
    "CZK" : "CZ",
    "DJF" : "DJ",
    "DKK" : "DK",
    "DOP" : "DO",
    "DZD" : "DZ",
    "ECS" : "EC",
    "EEK" : "EE",
    "EGP" : "EG",
    "ETB" : "ET",
    "EUR" : "FR",
    "FJD" : "FJ",
    "FKP" : "FK",
    "GBP" : "GB",
    "GEL" : "GE",
    "GGP" : "GG",
    "GHS" : "GH",
    "GIP" : "GI",
    "GMD" : "GM",
    "GNF" : "GN",
    "GTQ" : "GT",
    "GYD" : "GY",
    "HKD" : "HK",
    "HNL" : "HN",
    "HRK" : "HR",
    "HTG" : "HT",
    "HUF" : "HU",
    "IDR" : "ID",
    "ILS" : "IL",
    "INR" : "IN",
    "IQD" : "IQ",
    "IRR" : "IR",
    "ISK" : "IS",
    "JMD" : "JM",
    "JOD" : "JO",
    "JPY" : "JP",
    "KES" : "KE",
    "KGS" : "KG",
    "KHR" : "KH",
    "KMF" : "KM",
    "KPW" : "KP",
    "KRW" : "KR",
    "KWD" : "KW",
    "KYD" : "KY",
    "KZT" : "KZ",
    "LAK" : "LA",
    "LBP" : "LB",
    "LKR" : "LK",
    "LRD" : "LR",
    "LSL" : "LS",
    "LTL" : "LT",
    "LVL" : "LV",
    "LYD" : "LY",
    "MAD" : "MA",
    "MDL" : "MD",
    "MGA" : "MG",
    "MKD" : "MK",
    "MMK" : "MM",
    "MNT" : "MN",
    "MOP" : "MO",
    "MRO" : "MR",
    "MTL" : "MT",
    "MUR" : "MU",
    "MVR" : "MV",
    "MWK" : "MW",
    "MXN" : "MX",
    "MYR" : "MY",
    "MZN" : "MZ",
    "NAD" : "NA",
    "XPF" : "NC",
    "NGN" : "NG",
    "NIO" : "NI",
    "NPR" : "NP",
    "NZD" : "NZ",
    "OMR" : "OM",
    "PAB" : "PA",
    "PEN" : "PE",
    "PGK" : "PG",
    "PHP" : "PH",
    "PKR" : "PK",
    "PLN" : "PL",
    "PYG" : "PY",
    "QAR" : "QA",
    "RON" : "RO",
    "RSD" : "RS",
    "RUB" : "RU",
    "RWF" : "RW",
    "SAR" : "SA",
    "SBD" : "SB",
    "SCR" : "SC",
    "SDG" : "SD",
    "SEK" : "SE",
    "SGD" : "SG",
    "SKK" : "SK",
    "SLL" : "SL",
    "SOS" : "SO",
    "SRD" : "SR",
    "STD" : "ST",
    "SVC" : "SV",
    "SYP" : "SY",
    "SZL" : "SZ",
    "THB" : "TH",
    "TJS" : "TJ",
    "TMT" : "TM",
    "TND" : "TN",
    "TOP" : "TO",
    "TRY" : "TR",
    "TTD" : "TT",
    "TWD" : "TW",
    "TZS" : "TZ",
    "UAH" : "UA",
    "UGX" : "UG",
    "USD" : "US",
    "UYU" : "UY",
    "UZS" : "UZ",
    "VEF" : "VE",
    "VND" : "VN",
    "VUV" : "VU",
    "YER" : "YE",
    "ZAR" : "ZA",
    "ZMK" : "ZM",
    "ZWD" : "ZW"


Lastly, You have to create a JavaScript file with the name of script.js and paste the given codes in your JavaScript file. You’ve to create a file with .js extension and remember you have to pass your API key in the API URL otherwise this currency converter won’t work and it returns “something went wrong” error. You can get this key from the official ExchageRateAPI site for free.

const dropList = document.querySelectorAll("form select"),
fromCurrency = document.querySelector(".from select"),
toCurrency = document.querySelector(".to select"),
getButton = document.querySelector("form button");

for (let i = 0; i < dropList.length; i++) {
    for(let currency_code in country_list){
        let selected = i == 0 ? currency_code == "USD" ? "selected" : "" : currency_code == "NPR" ? "selected" : "";
        let optionTag = `<option value="${currency_code}" ${selected}>${currency_code}</option>`;
        dropList[i].insertAdjacentHTML("beforeend", optionTag);
    dropList[i].addEventListener("change", e =>{

function loadFlag(element){
    for(let code in country_list){
        if(code == element.value){
            let imgTag = element.parentElement.querySelector("img");
            imgTag.src = `${country_list[code].toLowerCase()}.png`;

window.addEventListener("load", ()=>{

getButton.addEventListener("click", e =>{

const exchangeIcon = document.querySelector("form .icon");
exchangeIcon.addEventListener("click", ()=>{
    let tempCode = fromCurrency.value;
    fromCurrency.value = toCurrency.value;
    toCurrency.value = tempCode;

function getExchangeRate(){
    const amount = document.querySelector("form input");
    const exchangeRateTxt = document.querySelector("form .exchange-rate");
    let amountVal = amount.value;
    if(amountVal == "" || amountVal == "0"){
        amount.value = "1";
        amountVal = 1;
    exchangeRateTxt.innerText = "Getting exchange rate...";
    let url = `${fromCurrency.value}`;
    fetch(url).then(response => response.json()).then(result =>{
        let exchangeRate = result.conversion_rates[toCurrency.value];
        let totalExRate = (amountVal * exchangeRate).toFixed(2);
        exchangeRateTxt.innerText = `${amountVal} ${fromCurrency.value} = ${totalExRate} ${toCurrency.value}`;
    }).catch(() =>{
        exchangeRateTxt.innerText = "Something went wrong";

Also Read : Facebook Wow Reaction Emoji in HTML & CSS

If you wann to check the demo of this code, then you can check using below demo button.


Click on the following download button to download all source code files of  Currency Converter App directly on your computer.


Final Word

In this way, we can build currency converter app using html, css & JavaScriptI hope you all like this tutorial. Keep with us for next tutorial. if you wann the source code of this code you can get this on our github account. If you have any query please free to contact us Or comment below.

Build A Currency Converter App in HTML CSS & JavaScript

Published on 04-Jan-2022 11:00:42

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