Your website load time has a direct impact on user experience and your Google page ranking. Image file size has a direct impact on your website loading speed. This means that image file size can directly correlate with how many visitors see your site and the quality of their experience. In short, compressing your image size can help bring more users to your site and keep them there for longer.

In this article, you’ll learn how image compression works and some tips for compressing your images effectively.

How Do You Compress Images?

You compress images using codecs, either directly or through tools that integrate the codecs. Codecs are programs that encode and decode images, video, or audio. These programs allow you to specify the format of media files as well as file properties, like the size or quality. There are both proprietary and open-source codecs. The type of codecs you can use depends on the image editing tools you choose to use.

When compressing files, you can choose to use either lossy or lossless compression. Lossy compression combines the pixel data of images, reducing the image file size by reducing the overall resolution. It permanently eliminates image data but results in much smaller images. Lossy compression is typically used for websites and other cases where size is more important than quality.

Lossless compression reduces image size assigning duplicate data to variables or parameters, which are then referenced to save space. You can also use it to reduce image size by removing unnecessary metadata or header and footer information. With lossless compression, you do not lose any image data but you also cannot compress files as small as with lossy compression. It is typically used for image archiving or when images need to be further processed.

Why Should You Compress Image Files?

An image is worth a thousand words, and given how short our attention spans in 2021 are, adding some images to your website would be an excellent idea. In some cases, it might even be a necessity. If you are running an eCommerce website, or want to sell any type of products, then your customers aren’t likely to trust your word only – they will demand to see some photos. 

However, even if you are running a website that isn’t primarily focused on photo content, you should consider adding some photos here and there to help you retain the attention of your audience. Unfortunately, although photos make your website look more interesting, a large number of images will make your website slower. 

It might seem like a fair price at first, as without images, your page would look bare, but it doesn’t mean that you won’t face some negative consequences as well. This is why compressing image files is important.

One of the most important benefits of compressing images is improved page load time. There are dozens of factors that affect how long it will take for a page to load, and some of those include its design, and hosting servers, but also the type and weight of different elements, including images. 

There are also other factors, such as user location or browser type, but when it comes to these, a website owner cannot do much. If you compress image files on your website, you’ll improve its performance. Now, page load time is extremely important and has an effect on things like your website’s position in SERPs, the number of conversions, or user experience.

Your Website’s Rankings

Internet users might dislike slow websites, and so does Google. If you are wondering whether page load time is really that important, you should know that it is one of the factors that affect a website’s position in SERPs (Search Engine Results Pages). Because of that, if your page takes ages to load, its rankings will suffer, and as a consequence, fewer people will know about your website’s existence. 

Though page load time is not by any means the only factor that affects the position of your page in SERPs, you should pay attention to it if you care about SEO. If your website is nowhere to be found, or at least not in the top positions for keywords that are relevant to your niche, then your organic traffic will suffer. 

Now, if you are running an eCommerce business with no brick-and-mortar shops, your business will not thrive without digital marketing, and SEO is a huge part of this.

The Number of Conversions

Though page load time is correlated with the website’s position in SERPs, it is possible that internet users will be able to find your website, such as through Facebook or Google Ads. It might also be the case that despite slow page load times, other factors will more than make up for this, and as an effect, your site will still rank in one of the top positions. 

However, none of this will matter much, as ‘patient’ is not the word that accurately describes internet users. If your page takes more than 3 seconds to load, almost half of the users will leave it. It doesn’t matter if your eCommerce store has better prices than your competitors or whether the quality of your products is superior – if internet users leave your page before it loads, it won’t help you. 

No matter what type of website you run, there is a high chance that internet users could find a similar one but with a faster page load time with only a couple of clicks. A high number of images will make your website more interesting, but if they aren’t compressed, they could do more harm than good.

User Experience

Another reason why page load speed is important to your website, no matter whether it’s a blog or an online shop, is that it affects user experience. Even if users don’t leave your website before it loads, they aren’t likely to be impressed if it takes 10 seconds to get from one page to another. 

As a consequence, they will spend a shorter time and the possibility that they’ll become your customers decreases. Apart from that, they’ll also be less likely to return to it at a later time. All of this is bad, no matter the type of business you run. That’s why you need to make sure that the size of images on your website is reasonable.

Can You Improve Page Load Time Without Compressing Images?

In a moment, we’ll present 4 tips for compressing images, but before we do that, we would like to point out that there is another way to decrease the page load time, even if the file size of images stays the same. 

Thanks to lazy loading, internet users won’t have to wait for all the photos on a page to load. Instead, more content will only start loading when they scroll down. This way, all the elements won’t load at the same time, which will have a positive impact on page load time.

4 Tips for Compressing Images

Now that you understand how compression works and a little more about your options, consider the following tips. These tips apply to any compression method you choose.

Compress Images From the Start

Make sure to compress your images before you upload them to your site or any Content Management System (CMS). Compressing before upload enables you to upload files more quickly and reduces your storage needs immediately. If you compress files only after uploading, you are more likely to retain duplicates. You also need to use more storage initially. 

Compressing files before upload can prevent you from accidentally using larger images than needed. Since only images with the proper compression are stored, you know that the images you are using are already web optimized. By limiting your selection, you make image assignments faster and easier.

Automate Your Compression

You may not be concerned about automating compression if you only have a few images to manage. If you have to process many images at once, however, automation can save you significant time and energy. It can also help when you need to compress images into several different formats or variations. 

Automation enables you to queue large numbers of images and process files when it is most convenient for you. With automation, you can more easily standardize your image compression, naming, and storage location. You can also more efficiently use your resources since automation can be scheduled to occur during low traffic hours.

You can automate image compression with either a custom script or a third-party service. Many services, like Digital Asset Management (DAM) systems or Content Delivery Networks (CDNs), include built-in features for automation. These features can enable you to perform batch processing or create responsive images on demand. 

Match Compression to Media Purpose

Most websites don’t require high definition images to deliver a high-quality user experience. For these sites, you can use lossy compression without sacrificing noticeable quality. The use of progressive JPEGs can also benefit the user experience. 

Progressive JPEGs are compressed in a way that allows them to be rendered from low quality to high-quality. Traditional rendering occurs from top to bottom. With progressive rendering, your site will load according to its final layout, and sections will not move as images load. This type of loading prevents your site from “jumping around” on users.

You can also dynamically serve a variety of compression formats according to the intended display device. For example, with smaller screens, like mobile devices, you can often use lower definition images than is needed for large desktop monitors. Dynamically serving images requires you to store more image files but can help you ensure the fastest user experience. 

Choose Image Formats Carefully

The image formats you choose are what determine the type and ratio of compression you can use. The format also determines the starting size of your images. For example, images saved in PNG format can only be compressed with lossless compression. PNG images start with larger file size than GIF or JPEG files. In general, JPEG images are the format you should default to for images. 

If possible, try to use vector graphics, saved in SVG, CGM, EPS, or XML format. Vector graphics require less storage space to begin with and can be easily compressed. You can use these images to create logos, backgrounds, and other images composed of geometric shapes. These graphics are scalable and retain their quality regardless of size. With vector graphics, you can create responsive websites with a single image file as opposed to creating images for each device specification.


Compressing your images can save you storage space, bandwidth costs and help you deliver a more enjoyable website experience. Luckily, compression is a process that can be done relatively quickly and easily. 

Hopefully, the tips provided here can help you take advantage of the benefits of image compression. If you need help determining where to start, consider these free compression tools.

About the Author

Gilad David Maayan is a technology writer who has worked with over 150 technology companies including SAP, Samsung NEXT, NetApp and Imperva, producing technical and thought leadership content that elucidates technical solutions for developers and IT leadership.

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