harunpehlivan/how-to-resize-and-compress-images.markdown

## how-to-resize-and-compress-images.markdown

      
    Raw
  

              how-to-resize-and-compress-images.markdown
            
          
    How to Resize and Compress Images

A Pen by HARUN PEHLİVAN on CodePen.
License.

  
## index.html
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="style.css">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="script.js" defer></script>
</head>

<body>
    <div class="wrapper">
        <div class="upload-box">
            <input type="file" accept="image/*" hidden>
            <img src="http://bit.ly/3ATfPAV" alt="">
            <p>Browse File to Upload</p>
        </div>
        <div class="content">
            <div class="row sizes">
                <div class="column width">
                    <label>Width</label>
                    <input type="number">
                </div>
                <div class="column height">
                    <label>Height</label>
                    <input type="number">
                </div>
            </div>
            <div class="row checkboxes">
                <div class="column ratio">
                    <input type="checkbox" id="ratio" checked>
                    <label for="ratio">Lock aspect ratio</label>
                </div>
                <div class="column quality">
                    <input type="checkbox" id="quality">
                    <label for="quality">Reduce quality</label>
                </div>
            </div>
            <button class="download-btn">Download Image</button>
        </div>
    </div>

</body>

</html>

## script.js
const uploadBox = document.querySelector(".upload-box"),
    previewImg = uploadBox.querySelector("img"),
    fileInput = uploadBox.querySelector("input"),
    widthInput = document.querySelector(".width input"),
    heightInput = document.querySelector(".height input"),
    ratioInput = document.querySelector(".ratio input"),
    qualityInput = document.querySelector(".quality input"),
    downloadBtn = document.querySelector(".download-btn");

let ogImageRatio;

const loadFile = (e) => {
    const file = e.target.files[0]; // getting first user selected file
    if (!file) return; // return if user hasn't selected any file
    previewImg.src = URL.createObjectURL(file); // passing selected file url to preview img src
    previewImg.addEventListener("load", () => { // once img loaded
        widthInput.value = previewImg.naturalWidth;
        heightInput.value = previewImg.naturalHeight;
        ogImageRatio = previewImg.naturalWidth / previewImg.naturalHeight;
        document.querySelector(".wrapper").classList.add("active");
    });
}

widthInput.addEventListener("keyup", () => {
    // getting height according to the ratio checkbox status
    const height = ratioInput.checked ? widthInput.value / ogImageRatio : heightInput.value;
    heightInput.value = Math.floor(height);
});

heightInput.addEventListener("keyup", () => {
    // getting width according to the ratio checkbox status
    const width = ratioInput.checked ? heightInput.value * ogImageRatio : widthInput.value;
    widthInput.value = Math.floor(width);
});

const resizeAndDownload = () => {
    const canvas = document.createElement("canvas");
    const a = document.createElement("a");
    const ctx = canvas.getContext("2d");

    // if quality checkbox is checked, pass 0.5 to imgQuality else pass 1.0
    // 1.0 is 100% quality where 0.5 is 50% of total. you can pass from 0.1 - 1.0
    const imgQuality = qualityInput.checked ? 0.5 : 1.0;

    // setting canvas height & width according to the input values
    canvas.width = widthInput.value;
    canvas.height = heightInput.value;

    // drawing user selected image onto the canvas
    ctx.drawImage(previewImg, 0, 0, canvas.width, canvas.height);

    // passing canvas data url as href value of <a> element
    a.href = canvas.toDataURL("image/jpeg", imgQuality);
    a.download = new Date().getTime(); // passing current time as download value
    a.click(); // clicking <a> element so the file download
}

downloadBtn.addEventListener("click", resizeAndDownload);
fileInput.addEventListener("change", loadFile);
uploadBox.addEventListener("click", () => fileInput.click());

## style.css
/* Import Google font - Poppins */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}
body{
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #e4702d;
}
.wrapper{
  width: 450px;
  height: 288px;
  padding: 30px;
  background: #fff;
  border-radius: 9px;
  transition: height 0.2s ease;
}
.wrapper.active{
  height: 537px;
}
.wrapper .upload-box{
  height: 225px;
  display: flex;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  border-radius: 5px;
  border: 2px dashed #afafaf;
}
.wrapper.active .upload-box{
  border: none;
}
.upload-box p{
  font-size: 1.06rem;
  margin-top: 20px;
}
.wrapper.active .upload-box p{
  display: none;
}
.wrapper.active .upload-box img{
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 5px;
}
.wrapper .content{
  opacity: 0;
  margin-top: 28px;
  pointer-events: none;
}
.wrapper.active .content{
  opacity: 1;
  pointer-events: auto;
  transition: opacity 0.5s 0.05s ease;
}
.content .row{
  display: flex;
  justify-content: space-between;
}
.content .row .column{
  width: calc(100% / 2 - 15px);
}
.row .column label{
  font-size: 1.06rem;
}
.sizes .column input{
  width: 100%;
  height: 49px;
  outline: none;
  margin-top: 7px;
  padding: 0 15px;
  font-size: 1.06rem;
  border-radius: 4px;
  border: 1px solid #aaa;
}
.sizes .column input:focus{
  padding: 0 14px;
  border: 2px solid #927DFC;
}
.content .checkboxes{
  margin-top: 20px;
}
.checkboxes .column{
  display: flex;
  align-items: center;
}
.checkboxes .column input{
  width: 17px;
  height: 17px;
  margin-right: 9px;
  accent-color: #927DFC;
}
.content .download-btn{
  width: 100%;
  color: #fff;
  outline: none;
  border: none;
  cursor: pointer;
  font-size: 1.06rem;
  border-radius: 5px;
  padding: 15px 0;
  margin: 30px 0 10px;
  background: #927DFC;
  text-transform: uppercase;
}
	<!DOCTYPE html>
	<html lang="en" dir="ltr">
	<head>
	<meta charset="utf-8">
	<link rel="stylesheet" href="style.css">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<script src="script.js" defer></script>
	</head>

	<body>
	<div class="wrapper">
	<div class="upload-box">
	<input type="file" accept="image/*" hidden>
	<img src="http://bit.ly/3ATfPAV" alt="">
	<p>Browse File to Upload</p>
	</div>
	<div class="content">
	<div class="row sizes">
	<div class="column width">
	<label>Width</label>
	<input type="number">
	</div>
	<div class="column height">
	<label>Height</label>
	<input type="number">
	</div>
	</div>
	<div class="row checkboxes">
	<div class="column ratio">
	<input type="checkbox" id="ratio" checked>
	<label for="ratio">Lock aspect ratio</label>
	</div>
	<div class="column quality">
	<input type="checkbox" id="quality">
	<label for="quality">Reduce quality</label>
	</div>
	</div>
	<button class="download-btn">Download Image</button>
	</div>
	</div>

	</body>

	</html>
	const uploadBox = document.querySelector(".upload-box"),
	previewImg = uploadBox.querySelector("img"),
	fileInput = uploadBox.querySelector("input"),
	widthInput = document.querySelector(".width input"),
	heightInput = document.querySelector(".height input"),
	ratioInput = document.querySelector(".ratio input"),
	qualityInput = document.querySelector(".quality input"),
	downloadBtn = document.querySelector(".download-btn");

	let ogImageRatio;

	const loadFile = (e) => {
	const file = e.target.files[0]; // getting first user selected file
	if (!file) return; // return if user hasn't selected any file
	previewImg.src = URL.createObjectURL(file); // passing selected file url to preview img src
	previewImg.addEventListener("load", () => { // once img loaded
	widthInput.value = previewImg.naturalWidth;
	heightInput.value = previewImg.naturalHeight;
	ogImageRatio = previewImg.naturalWidth / previewImg.naturalHeight;
	document.querySelector(".wrapper").classList.add("active");
	});
	}

	widthInput.addEventListener("keyup", () => {
	// getting height according to the ratio checkbox status
	const height = ratioInput.checked ? widthInput.value / ogImageRatio : heightInput.value;
	heightInput.value = Math.floor(height);
	});

	heightInput.addEventListener("keyup", () => {
	// getting width according to the ratio checkbox status
	const width = ratioInput.checked ? heightInput.value * ogImageRatio : widthInput.value;
	widthInput.value = Math.floor(width);
	});

	const resizeAndDownload = () => {
	const canvas = document.createElement("canvas");
	const a = document.createElement("a");
	const ctx = canvas.getContext("2d");

	// if quality checkbox is checked, pass 0.5 to imgQuality else pass 1.0
	// 1.0 is 100% quality where 0.5 is 50% of total. you can pass from 0.1 - 1.0
	const imgQuality = qualityInput.checked ? 0.5 : 1.0;

	// setting canvas height & width according to the input values
	canvas.width = widthInput.value;
	canvas.height = heightInput.value;

	// drawing user selected image onto the canvas
	ctx.drawImage(previewImg, 0, 0, canvas.width, canvas.height);

	// passing canvas data url as href value of <a> element
	a.href = canvas.toDataURL("image/jpeg", imgQuality);
	a.download = new Date().getTime(); // passing current time as download value
	a.click(); // clicking <a> element so the file download
	}

	downloadBtn.addEventListener("click", resizeAndDownload);
	fileInput.addEventListener("change", loadFile);
	uploadBox.addEventListener("click", () => fileInput.click());
	/* Import Google font - Poppins */
	@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600&display=swap');
	*{
	margin: 0;
	padding: 0;
	box-sizing: border-box;
	font-family: 'Poppins', sans-serif;
	}
	body{
	display: flex;
	align-items: center;
	justify-content: center;
	min-height: 100vh;
	background: #e4702d;
	}
	.wrapper{
	width: 450px;
	height: 288px;
	padding: 30px;
	background: #fff;
	border-radius: 9px;
	transition: height 0.2s ease;
	}
	.wrapper.active{
	height: 537px;
	}
	.wrapper .upload-box{
	height: 225px;
	display: flex;
	cursor: pointer;
	align-items: center;
	justify-content: center;
	flex-direction: column;
	border-radius: 5px;
	border: 2px dashed #afafaf;
	}
	.wrapper.active .upload-box{
	border: none;
	}
	.upload-box p{
	font-size: 1.06rem;
	margin-top: 20px;
	}
	.wrapper.active .upload-box p{
	display: none;
	}
	.wrapper.active .upload-box img{
	width: 100%;
	height: 100%;
	object-fit: cover;
	border-radius: 5px;
	}
	.wrapper .content{
	opacity: 0;
	margin-top: 28px;
	pointer-events: none;
	}
	.wrapper.active .content{
	opacity: 1;
	pointer-events: auto;
	transition: opacity 0.5s 0.05s ease;
	}
	.content .row{
	display: flex;
	justify-content: space-between;
	}
	.content .row .column{
	width: calc(100% / 2 - 15px);
	}
	.row .column label{
	font-size: 1.06rem;
	}
	.sizes .column input{
	width: 100%;
	height: 49px;
	outline: none;
	margin-top: 7px;
	padding: 0 15px;
	font-size: 1.06rem;
	border-radius: 4px;
	border: 1px solid #aaa;
	}
	.sizes .column input:focus{
	padding: 0 14px;
	border: 2px solid #927DFC;
	}
	.content .checkboxes{
	margin-top: 20px;
	}
	.checkboxes .column{
	display: flex;
	align-items: center;
	}
	.checkboxes .column input{
	width: 17px;
	height: 17px;
	margin-right: 9px;
	accent-color: #927DFC;
	}
	.content .download-btn{
	width: 100%;
	color: #fff;
	outline: none;
	border: none;
	cursor: pointer;
	font-size: 1.06rem;
	border-radius: 5px;
	padding: 15px 0;
	margin: 30px 0 10px;
	background: #927DFC;
	text-transform: uppercase;
	}