How to Change Image Size in HTML: Your Quick and Easy Guide

By Cristian G. Guasch •  Updated: 09/18/23 •  8 min read

When it comes to creating a visually engaging website, images play a crucial role. However, controlling the size of these images is equally paramount to ensure your site retains its aesthetic appeal and user-friendly interface. In HTML, changing an image’s size doesn’t have to be a daunting task.

The first thing you need to know about modifying image sizes in HTML is that it’s done through specific attributes in the <img> tag. These are the width and height attributes. You simply specify the desired dimensions for your images by altering these values.

It’s also essential to understand that while manipulating these numbers will indeed change your image size, caution should be exercised. Incorrectly sizing your pictures could lead to distortion or pixelation—ultimately affecting the quality of visuals on your webpage. Stick around as I dive deeper into how you can effectively use HTML for resizing your images without losing their original charm!

Understanding HTML and Image Size

Diving straight into the world of HTML, it’s crucial to grasp how image size manipulation works. After all, images play a vital role in enhancing user experience on any website. Now, let’s delve into this intriguing topic.

HTML or HyperText Markup Language is the standard language for creating web pages. But here’s the catch – HTML itself doesn’t directly deal with image sizes! Instead, it provides tags that are used by browsers to interpret and display content like text, images, and other elements.

Let’s take an example:

<img src="image.jpg" width="500" height="600">

In this simple line of code, we’re handling image size by specifying the ‘width’ and ‘height’ attributes within the ‘img’ tag. The values are in pixels which gives you precise control over your image dimensions.

But what if I told you there’s more than one way to skin a cat? That’s right – besides directly setting pixel values for width and height in HTML, you can also utilize CSS (Cascading Style Sheets) for resizing images. Using CSS allows more flexibility as it separates styling from content.

Here’s an example:

<img src="image.jpg" style="width:500px;height:600px;">

While these methods offer straightforward ways to control image size in HTML, remember that maintaining aspect ratio is essential to prevent distortion. If only one attribute (either width or height) is specified, the browser automatically adjusts the unspecified attribute to maintain this ratio.

So there you have it! A basic understanding of managing image sizes in HTML is not just about adding numbers; it’s about striking a balance between design aesthetics and user experience.

Steps to Change Image Size in HTML

Diving straight into it, the first thing you’ve got to know is that HTML allows us to alter the size of an image using specific attributes. This capability is quite handy when we need a particular picture to fit perfectly with our web content’s overall layout.

Let’s begin with the basics. The width and height are the two primary attributes we use in HTML for resizing images. Here’s how it works:

<img src="your_image.jpg" width="500" height="600">

You’ll notice I’ve set values for both width and height in this snippet of code. These dimensions are measured in pixels, so what we’re doing here essentially is setting the width of our image to 500 pixels and its height to 600 pixels.

But don’t let that limit your creativity! You can also specify these dimensions as a percentage value relative to their parent element:

<img src="your_image.jpg" width="50%" height="60%">

Here, instead of absolute pixel values, I’m resizing my image relative to its container. Therefore, if an image’s parent element has a width of 1000px, then an image with a width attribute set as “50%” would render at 500px wide.

It’s important not just for aesthetics but for improving your website’s loading speed too because large-size images take longer time load which could affect user experience negatively.

However, keep this crucial detail in mind: While changing the size of an image using HTML might seem straightforward enough, be careful with extreme changes. Dramatically increasing or decreasing your original image’s size could lead it becoming distorted or pixelated – nobody wants that!

And remember: Always ensure your images maintain their aspect ratio unless you purposely want them stretched or squished!

There you have it – all about resizing images using HTML! Practice makes perfect, so why not try out these steps yourself? You’ll be a pro in no time.

Effects of Altering the Image Size on Website Performance

Let’s dive right into it. Changing an image size in HTML can significantly impact your website’s performance, and here’s why. When you use large images on your website, they consume a lot of bandwidth when loading. This means your site takes longer to load, which could potentially frustrate visitors and lead them to leave.

Here’s a little HTML example for you:

<img src="image.jpg" alt="Sample Image" width="500" height="600">

In this snippet, the image size is set to 500×600 pixels. If “image.jpg” is originally much larger than that, say 2000×2400 pixels, the browser still loads the full-sized image then scales it down to fit these dimensions. That’s quite a heavy lift!

Consider another scenario:

<img src="image.jpg" alt="Sample Image" style="width:50%;height:auto;">

In this case, I’ve used CSS within the HTML tag to resize the image dynamically based on the viewer’s screen size (50% of its original size). While this might seem like a neat trick for responsive design, it could slow down page loading times if not managed properly.

So what happens when we use smaller images? Well, small images load faster because they take up less bandwidth. But beware! If an image is too small and gets stretched out over a large area on your webpage—like as a background or banner—the quality may deteriorate resulting in pixelation.

<img src="small-image.jpg" alt="Small Sample Image" style="width:100%;height:auto;">

The above code shows how stretching a small image (“small-image.jpg”) over an entire webpage width can harm visual quality.

Now let’s talk numbers – according to HTTP Archive, as of October 2021, images make up on average 49% of a total webpage’s weight. That’s nearly half! This underscores the crucial role that optimized image sizing plays in maintaining speedy and efficient website performance.

Average percentage of total webpage weight made up by images (Oct 2021)49%

Here are some tips to keep in mind:

Remember, a slow-loading website can deter visitors, so it’s essential you pay attention to your site’s image sizes.

Common Mistakes When Changing Image Sizes in HTML

Navigating the world of HTML can feel like a daunting task, especially when it comes to handling images. I’ve seen many beginners and even experienced coders make common mistakes when trying to change image sizes in HTML. Let’s dive into some of those missteps.

First off, one common error is using incorrect syntax for the height and width attributes. The correct way is <img src="image.jpg" alt="My Image" width="500" height="600">. Note that there are no units after the numbers – you don’t need to add ‘px’ or any other units. Using them might result in your image not displaying correctly.

Another prevalent mistake is neglecting to maintain an image’s aspect ratio. If you’re changing both the width and height values manually, remember to keep the proportions consistent. Otherwise, your picture could end up distorted.

Here’s an example:

<!-- Incorrect -->
<img src="image.jpg" alt="Image Description" width="700" height="200">

<!-- Correct -->
<img src="image.jpg" alt="Image Description" width="700" height="525">

In this case, if we want to increase the original image size from 500×375 pixels (with a ratio of 4:3) to a width of 700 pixels, we should also proportionately adjust its height value – making it 525 instead of just randomly assigning it as 200.

Next on our list is forgetting about responsive design. In today’s mobile-centric world, ensuring your website looks great on all devices is crucial. But hard-coding pixel values can lead us into trouble here because these fixed sizes may not translate well across different screen resolutions and orientations.

For instance:

<!-- Not ideal for responsive design -->
<img src="image.jpg" alt= "An Image Description" width="500" height="600">

<!-- Better for responsive design -->
<img src="image.jpg" alt= "An Image Description" style="width:100%; height:auto;">

In the second example, we’re using percentages instead of fixed pixel values. This makes the image size relative to its parent element and thus more adaptable to different screen sizes.

Lastly, a mistake I’ve seen far too often is forgetting to add an alt attribute. While this doesn’t impact image size directly, it’s crucial for SEO and web accessibility. Always ensure you have meaningful alt text associated with your images.

Avoiding these common pitfalls will not only make your website look better but also improve user experience and SEO rankings. So next time you’re tweaking image sizes in HTML, keep these points in mind!

Cristian G. Guasch

Hey! I'm Cristian Gonzalez, I created HTML Easy to help you learn HTML easily and fast.

Related articles