How to convert a file to zip file and download it using Node.js ?

Last Updated : 01 Aug, 2024

The Zip files are a common way of storing compressed files and folders. In this article, I’ll demonstrate how to convert the file to zip format by using the adm-zip module (NPM PACKAGE).

Uses of ADM-ZIP

compress the original file and change them to zip format.
update/delete the existing files(.zip format).

Installation of ADM-ZIP:

Step 1: Install the module using the below command in the terminal.

npm install adm-zip

Step 2: Check the version of the installed module by using the below command

npm version adm-zip

Project Structure:

final project

We are going to change this upload_data folder to a zip file using the adm-zip module!

upload_data FOLDER

Code for conversion and downloading zip file:

JavaScript

// express is a node framework that is helps in creating // 2 or more web-pages application const express = require('express')  // filesystem is a node module that allows us to work with // the files that are stored on our pc const file_system = require('fs')  // it is an npm package.this is to be required in our JS // file for the conversion of data to a zip file! const admz = require('adm-zip')  // stores the express module into the app variable! const app = express()  // this is the name of specific folder which is to be // changed into zip file1 var to_zip = file_system.readdirSync(__dirname + '/' + 'upload_data')  // this is used to request the specific file and then print // the data in it! app.get('/', function (req, res) {     res.sendFile(__dirname + '/' + 'index.html')       // zp is created as an object of class admz() which     // contains functionalities     const zp = new admz();       // this is the main part of our work!     // here for loop check counts and passes each and every     // file of our folder "upload_data"     // and convert each of them to a zip!     for (let k = 0; k < to_zip.length; k++) {         zp.addLocalFile(__dirname + '/' + 'upload_data' + '/' + to_zip[k])     }       // here we assigned the name to our downloaded file!     const file_after_download = 'downloaded_file.zip';      // toBuffer() is used to read the data and save it     // for downloading process!     const data = zp.toBuffer();       // this is the code for downloading!     // here we have to specify 3 things:     // 1. type of content that we are downloading     // 2. name of file to be downloaded     // 3. length or size of the downloaded file!      res.set('Content-Type', 'application/octet-stream');     res.set('Content-Disposition', `attachment; filename=${file_after_download}`);     res.set('Content-Length', data.length);     res.send(data);  })  // this is used to listen a specific port! app.listen(7777, function () {     console.log('port is active at 7777'); })

Steps to run the program:

Open the terminal at the desired local and make sure that u have downloaded the adm-zip package using the following command.

npm install adm-zip

Run the app.js file using the following command.

node app.js

app is running

Open the browser and open localhost:7777 and then the upload_data folder gets converted to a zip file and gets downloaded!

changed to zip file

Output: Representing the whole procedure for converting files to zip files with the help of the following gif, so in this way, you can change your folder to a zip file and then download it!