resize uploaded images on front end

Usage no npm install needed!

<script type="module">
  import shellophobiaTransformImageJs from 'https://cdn.skypack.dev/@shellophobia/transform-image-js';



Build Status Version License minified size

transform-image-js is a library to perform transformations on an image file e.g. resize an image within defined constraints and also allows to adjust the quality of image. One of the use cases is when you want to perform a size optimization on the image before uploading.

Getting started


Using npm:

npm i @shellophobia/transform-image-js

Using yarn:

yarn add @shellophobia/transform-image-js

Using jsDelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/@shellophobia/transform-image-js/lib/transform-image-js.min.js"></script>

Using unpkg CDN:

<script src="https://unpkg.com/@shellophobia/transform-image-js/lib/transform-image-js.min.js"></script>



in CommonJS:

const transformImage = require("@shellophobia/transform-image-js")

in ES6:

import transformImage from '@shellophobia/transform-image-js';

Resize image to max 500x500 with quality as 0.9:

Vanilla JS and HTML
<input id="demo" type="file" onchange="handleUpload">
function handleUpload(e){
  const file = e.target.files[0];
  // The library will add a property `transformImageJS` on window once you import it
  const transformImage = new transformImageJS.TransformImage({});
  transformImage.resizeImage(file, {maxHeight: 500, maxWidth:500, quality:0.9}).then(res=>{
    //The response returns an object that has the output blob in output attribute and has metadata for image sizes before and after transformation
  }).catch(err => {
    // handle error

// using async function
async function handleUpload(e) {
  const file = e.target.files[0];
  const transformImage = new transformImageJS.TransformImage({});
  try {
    const res = await transformImage.resizeImage(file, {maxHeight: 500, maxWidth:500, quality:0.9});
  } catch(e) {
    // handle error
React JSX
import React from "react";
import transformImage from "@shellophobia/transform-image-js";

const handleUpload = async (e) => {
  const file = e.target.files[0];
  const transformImage = new transformImage({});
  try {
    const res = await transformImage.resizeImage(file, {maxHeight: 500, maxWidth:500, quality:0.9});
  } catch (e) {

export default function App() {
  return (
    <div className="App">
      <input type="file" onChange={handleUpload} />


Initialization options


Following options can be passed during initialization of transformImage that returns an object on which methods can be called


Name Type Description Default
sizeLimit int the byte size limit for the input file/blob 16777216 bytes = 16MB
outputType enum defines the output object format. Allowed values :- blob/base64/file blob
allowedFileTypes []string allowed types for the input file/blob e.g. PNG, JPEG, JPG ["jpg", "png", "jpeg"]


resizeImage(imageFile, options, fileName) => {Promise}


Resize an image file


Name Type Description Required Default
image File/Blob File object / Blob to be resized Yes N/A
options Object Additional options described below. The values can also override the TransformImage options No {}
fileName string Name of the file if outputType is file (Optional) No ""
Name Type Description Default
maxWidth int the max width for the file in px 500
maxHeight int the max height for the file in px 500
quality float a value between 0 and 1 to denote the quality of the output image 0.9


Promise that resolves to the output object

Name Type Description
output blob/base64 string Blob or base64 string based on configuration
metadata object Metadata about initial image dimensions and final image dimensions
Name Type Description
originalHeight int Original image height
originalWidth int Original image width
resizedHeight int Resized image height
resizedWidth int Resized image width

JQuery Plugin

image_compress_plugin is a jquery plugin that allows to add a file upload and compress functionality.



<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/@shellophobia/transform-image-js/jquery_plugin/image_compress_plugin.js"></script>


<p>This is a demo for the resize image jquery plugin. Feel free to go through the source code 
<a href="https://github.com/shellophobia/UploadCompressImage/blob/master/jquery_plugin/image_compress_plugin.js">here</a></p>
<div id="fileinput">
  <button class="btn-upload"><i class="fas fa-cloud-upload-alt"></i> Click Here to Upload</button>
  <p class="drag-p">Or Drag N Drop the file</p>
  <input type="file" multiple="true">
<div id="preview"></div>

<script type="text/javascript" src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/@shellophobia/transform-image-js/jquery_plugin/image_compress_plugin.js"></script>
<script type="text/javascript">
$(document).ready(function() {
    enablePreview: true,
    appendFileInput: false,
    autoSubmit: false,
    previewSelector: "#preview"

Configuration gist for jquery plugin