Currency Converter App

Author: @official-carledwardp
Live app:
Last updated on: Oct 3, 2021 8:00PM (+08:00)


This is the first challenge from our new and upcoming Discord server. This app will be used to convert 200+ supported currencies from one to another. The “Currency Code” field (ex. USD) follows the standard ISO 4217 Three Letter Currency Code [1]. This ensures clarity and reduces errors in any exchange activities.

The app is a Next.JS [2] project which utilizes the SSR (Server Side Rendering) feature and uses the third-party data fetching service, SWR [3] (Fun Fact! The developers of NextJS also made this service). This makes sure that data will always be available whenever you use this app.

Try my project!

To run:

  1. Clone repository

git clone
  1. Run project

cd ~path-to/currency-converter
yarn dev

A great feature of Nextjs, Server Side Props. This ensures that you will have the currency options on load:

export async function getServerSideProps() {
  let response = await api().get(`api-end-point`)

  return {
    props: {
      currencies: response.currencies || [],

The use case of SWR in this project is to cache data and make sure that the app will not have duplicate api calls:

const { data } = useSWR(`/api-end-point`)

SWR Global config:
Documentation for the options can be found here

    fetcher: (url) => fetch(url).then((response) => response.json()),
    revalidateOnFocus: false, // Do not revalidate on window refocus
    dedupingInterval: 1000 * 60 * 60 * 24, // 1 day
    onError: errorCallback, // Callback function if there are errors
    errorRetryCount: 2, // Retry limit


CSS Framework used: Chakra UI [4]
Responsive and supports both light and dark mode. Just click the gear icon at the bottom to toggle color mode.

Dark Desktop
Light Desktop
Dark Mobile
Light Mobile


Currently, these are the limitations of this app:

  1. The data updates only once a day.
  2. The currency name is not returned, only the code (i.e. USD, PHP). It would be better if you can see the currency name alongside the code for a much better user experience.

These limitations can be overcome either by upgrading the plan or by finding another API service which returns the currency name.


[1] ISO 4217 Three Letter Currency Code
[2] Next.JS
[3] SWR
[4] ChakraUI

About Me

I’m Carl Edward, a self-taught developer. I started on October 2020 and have been studying, working, and improving since then. I had a 6-month experience in a corporate setting.