How to import CSV files in JavaScript with UseCSV

Jun 1, 2022

Importing CSV and Excel files is a feature everyone has to build eventually. Whilst there are a handful of CSV parser libraries out there, you're left to build the UI yourself. We're going to show you how to add CSV file import with a delightful UI to your vanilla Javascript app in just a few minutes.

What is UseCSV?

UseCSV is an all-in-one CSV import product that gives you a delightful CSV importer experience for your users. All you have to do is drop-in the UseCSV JS library, and create a webhook endpoint to receive uploads. This takes away all the headaches of building CSV import functionality in-house .

Here's a sneak peak of what the import experience will be for your users (this opens in a modal inside your app):

Here are just a few of the awesome features of UseCSV:

  • Frontend libraries which add the UseCSV import button and modal to your app
  • Supports CSV and all Excel formats (xlsx, xls, xlt), including legacy Excel versions
  • Handles large import files
  • Includes a library of common validation rules to choose from

Without further ado, let's get started!

Setup your UseCSV account

You'll want to first grab a free UseCSV developer account. Once you've signed up and logged in, you'll see an Importer called "My First Importer" which has already been created for you.


Click the View button. Here you can configure your Importer. Note the Key and Webhook URL fields, we'll need these later on.


Head down to the Column section, where you can setup the data model for this Importer.


Click Add Column to create a new column, for example you could add a first_name column to begin with. Create as many columns as you like.


Add CSV import to your JavaScript app

Adding CSV importing via JavaScript is as easy as installing the @usecsv/js package and then dropping it into your code. Here is a walkthrough on how to do this.

Step 1: Install @usecsv/js package to your project

To install and use UseCSV for your CSV importing needs, you need to install the JavaScript package. This can be achieved through npm, yarn, or via CDN.

For npm, simply use the following:

npm install @usecsv/js

For yarn, use the following:

yarn add @usecsv/js

For CDN:

<script src=""></script>

Step 2: Drop the library into your project

The next step will help connect your JavaScript frontend to UseCSV and your import model.

The following steps will create an importButton and attach UseCSV library to your JavaScript frontend.

First, create the button in HTML. The import-data-button id lets you uniquely identify the specific DOM element you want to attach the importing functionality to.

... <button type="button" id="import-data-button">Import Data</button> ...

To initialize and set up UseCSV's JavaScript library for CSV importing, here is a sample code snippet that you can use. This will attach UseCSV's modal to the import-data-button DOM element and perform the necessary actions required to get your user's data to UseCSV.

var importButton = document.getElementById("import-data-button"); importButton.onclick = function () { useCsvPlugin({ importerKey: "your-importer-key", user: { userId: "12345" }, metadata: { anotherId: "1" } }); };

There are three parameters available. Here is a breakdown of what they are and what they do.

  • importerKey: this is a string value that is available in the admin panel of your UseCSV import model.
  • user: this value contains the details of your importing user. It is an optional parameter and can be useful for quickly identifying details about who is using the CSV importer.
  • metadata: This parameter allows you to attach an object containing any additional details you want about the CSV import. The parameters inside this object can be anything you want.

That's basically it for the JavaScript integration side for CSV importing. When you click on your import button, it should pop up a working modal.

Receive data from imports

There are two ways to receive data imports. The first is via a webhook. The second way is to keep the uploaded data local by passing an onData callback function to your UseCSV component. For more information about using the onData callback, check out the documentation for it here.

For this tutorial, we are going to be using the first method - receiving uploads to a Node.js backend as a webhook.

Add the webhook endpoint

To set up and run a simple Node.js server, create a new directory with a file called server.js.

In server.js, we'll start by requiring the http module. This module will give us the ability to create an HTTP server.

var http = require('http');

Next, we'll create an HTTP server. We'll set it to listen on port 8080.

http.createServer(function (req, res) { }).listen(8080);

Now that we have our server created, we need to write the code that will handle webhook requests. For this example, we'll simply log the request body to the console.

http.createServer(function (request, response) { request.on("data", function (data) { console.log("data", JSON.parse(data)); response.statusCode = 200; response.end(); }); }).listen(8080);

Now that our server is created and we're logging webhook requests, we just need to start it up. To do this, open up a terminal window and navigate to your project directory. Then, run the following command:

node server.js

Once your server is running, you can test it by making a webhook request to your endpoint. If everything is working properly, you should see the request body logged to the console.

To connect this webhook endpoint up with your UseCSV importer, you can use a free Cloudflare tunnel.

Start a Cloudflare tunnel:

cloudflared tunnel localhost:8080

If your Cloudflare commands are successful, you will get something like this:

2022-01-29T23:40:16Z INF Thank you for trying Cloudflare Tunnel. Doing so, without a Cloudflare account, is a quick way to experiment and try it out. However, be aware that these account-less Tunnels have no uptime guarantee. If you intend to use Tunnels in production you should use a pre-created named tunnel by following: 2022-01-29T23:40:16Z INF Requesting new quick Tunnel on 2022-01-29T23:40:17Z INF +--------------------------------------------------------------------------------------------+ 2022-01-29T23:40:17Z INF | Your quick Tunnel has been created! Visit it at (it may take some time to be reachable): | 2022-01-29T23:40:17Z INF | | 2022-01-29T23:40:17Z INF +--------------------------------------------------------------------------------------------+

Use the tunnel link and paste it into the Webhook URL field to finish connecting everything up.

We're ready to try your first import

Go back to your JavaScript app and click on Import Data to open the importer modal.

Upload your CSV file, match the columns and then click import.




Watch your node.js console log for the webhook payload. UseCSV will automatically split up the webhooks into batches of 1,000 rows.

Where to from here?

UseCSV makes it simple to add delightful CSV import to your app. There are many powerful features under the hood including themes and validation rules. Checkout the docs for more info.

Add CSV Import To Your App

Get Started free and start integrating UseCSV today

Add CSV Import To Your App

Get Started free

and start integrating UseCSV today

Add CSV Import To Your App

Get Started free

and start integrating UseCSV today